Project Gutenberg's etext, The Categories, by Aristotle

Copyright laws are changing all over the world, be sure to check
the copyright laws for your country before posting these files!!

Please take a look at the important information in this header.
We encourage you to keep this file on your own disk, keeping an
electronic path open for the next readers. Do not remove this.

**Welcome To The World of Free Plain Vanilla Electronic Texts**

**Etexts Readable By Both Humans and By Computers, Since 1971**

*These Etexts Prepared By Hundreds of Volunteers and Donations*

Information on contacting Project Gutenberg to get Etexts, and
further information is included below. We need your donations.

The Categories

by Aristotle

November, 2000 [Etext #2412]
[Last Update: January 12, 2002]

Project Gutenberg Etext, The Categories, by Aristotle
******This file should be named arist10.txt or******

Corrected EDITIONS of our etexts get a new NUMBER, arist11.txt
VERSIONS based on separate sources get new LETTER, arist10a.txt

Project Gutenberg Etexts are usually created from multiple editions,
all of which are in the Public Domain in the United States, unless a
copyright notice is included. Therefore, we usually do NOT keep any
of these books in compliance with any particular paper edition.

E-text supplied by Glyn Hughes^M

We are now trying to release all our books one month in advance
of the official release dates, leaving time for better editing.

Please note: neither this list nor its contents are final till
midnight of the last day of the month of any such announcement.
The official release date of all Project Gutenberg Etexts is at
Midnight, Central Time, of the last day of the stated month. A
preliminary version may often be posted for suggestion, comment
and editing by those who wish to do so. To be sure you have an
up to date first edition [] please check file sizes
in the first week of the next month. Since our ftp program has
a bug in it that scrambles the date [tried to fix and failed] a
look at the file size will have to do, but we will try to see a
new copy has at least one byte more or less.

Information about Project Gutenberg (one page)

We produce about two million dollars for each hour we work. The
time it takes us, a rather conservative estimate, is fifty hours
to get any etext selected, entered, proofread, edited, copyright
searched and analyzed, the copyright letters written, etc. This
projected audience is one hundred million readers. If our value
per text is nominally estimated at one dollar then we produce $2
million dollars per hour this year as we release thirty-six text
files per month, or 432 more Etexts in 1999 for a total of 2000+
If these reach just 10% of the computerized population, then the
total should reach over 200 billion Etexts given away this year.

The Goal of Project Gutenberg is to Give Away One Trillion Etext
Files by December 31, 2001. [10,000 x 100,000,000 = 1 Trillion]
This is ten thousand titles each to one hundred million readers,
which is only ~5% of the present number of computer users.

At our revised rates of production, we will reach only one-third
of that goal by the end of 2001, or about 3,333 Etexts unless we
manage to get some real funding; currently our funding is mostly
from Michael Hart's salary at Carnegie-Mellon University, and an
assortment of sporadic gifts; this salary is only good for a few
more years, so we are looking for something to replace it, as we
don't want Project Gutenberg to be so dependent on one person.

We need your donations more than ever!

All donations should be made to "Project Gutenberg/CMU": and are
tax deductible to the extent allowable by law. (CMU = Carnegie-
Mellon University).

For these and other matters, please mail to:

Project Gutenberg
P. O. Box 2782
Champaign, IL 61825

When all other email fails. . .try our Executive Director:
Michael S. Hart forwards to and
if your mail bounces from, I will still see it, if
it bounces from, better resend later on. . . .

We would prefer to send you this information by email.


To access Project Gutenberg etexts, use any Web browser
to view This site lists Etexts by
author and by title, and includes information about how
to get involved with Project Gutenberg. You could also
download our past Newsletters, or subscribe here. This
is one of our major sites, please email,
for a more complete list of our various sites.

To go directly to the etext collections, use FTP or any
Web browser to visit a Project Gutenberg mirror (mirror
sites are available on 7 continents; mirrors are listed

Example FTP session:

login: anonymous
password: your@login
cd pub/docs/books/gutenberg
cd etext90 through etext99 or etext00
dir [to see files]
get or mget [to get files. . .set bin for zip files]
GET GUTINDEX.?? [to get a year's listing of books, e.g., GUTINDEX.99]
GET GUTINDEX.ALL [to get a listing of ALL books]

**Information prepared by the Project Gutenberg legal advisor**

(Three Pages)

Why is this "Small Print!" statement here? You know: lawyers.
They tell us you might sue us if there is something wrong with
your copy of this etext, even if you got it for free from
someone other than us, and even if what's wrong is not our
fault. So, among other things, this "Small Print!" statement
disclaims most of our liability to you. It also tells you how
you can distribute copies of this etext if you want to.

By using or reading any part of this PROJECT GUTENBERG-tm
etext, you indicate that you understand, agree to and accept
this "Small Print!" statement. If you do not, you can receive
a refund of the money (if any) you paid for this etext by
sending a request within 30 days of receiving it to the person
you got it from. If you received this etext on a physical
medium (such as a disk), you must return it with your request.

tm etexts, is a "public domain" work distributed by Professor
Michael S. Hart through the Project Gutenberg Association at
Carnegie-Mellon University (the "Project"). Among other
things, this means that no one owns a United States copyright
on or for this work, so the Project (and you!) can copy and
distribute it in the United States without permission and
without paying copyright royalties. Special rules, set forth
below, apply if you wish to copy and distribute this etext
under the Project's "PROJECT GUTENBERG" trademark.

To create these etexts, the Project expends considerable
efforts to identify, transcribe and proofread public domain
works. Despite these efforts, the Project's etexts and any
medium they may be on may contain "Defects". Among other
things, Defects may take the form of incomplete, inaccurate or
corrupt data, transcription errors, a copyright or other
intellectual property infringement, a defective or damaged
disk or other etext medium, a computer virus, or computer
codes that damage or cannot be read by your equipment.

But for the "Right of Replacement or Refund" described below,
[1] the Project (and any other party you may receive this
etext from as a PROJECT GUTENBERG-tm etext) disclaims all
liability to you for damages, costs and expenses, including

If you discover a Defect in this etext within 90 days of
receiving it, you can receive a refund of the money (if any)
you paid for it by sending an explanatory note within that
time to the person you received it from. If you received it
on a physical medium, you must return it with your note, and
such person may choose to alternatively give you a replacement
copy. If you received it electronically, such person may
choose to alternatively give you a second opportunity to
receive it electronically.


Some states do not allow disclaimers of implied warranties or
the exclusion or limitation of consequential damages, so the
above disclaimers and exclusions may not apply to you, and you
may have other legal rights.

You will indemnify and hold the Project, its directors,
officers, members and agents harmless from all liability, cost
and expense, including legal fees, that arise directly or
indirectly from any of the following that you do or cause:
[1] distribution of this etext, [2] alteration, modification,
or addition to the etext, or [3] any Defect.

You may distribute copies of this etext electronically, or by
disk, book or any other medium if you either delete this
"Small Print!" and all other references to Project Gutenberg,

[1] Only give exact copies of it. Among other things, this
requires that you do not remove, alter or modify the
etext or this "small print!" statement. You may however,
if you wish, distribute this etext in machine readable
binary, compressed, mark-up, or proprietary form,
including any form resulting from conversion by word pro-
cessing or hypertext software, but only so long as

[*] The etext, when displayed, is clearly readable, and
does *not* contain characters other than those
intended by the author of the work, although tilde
(~), asterisk (*) and underline (_) characters may
be used to convey punctuation intended by the
author, and additional characters may be used to
indicate hypertext links; OR

[*] The etext may be readily converted by the reader at
no expense into plain ASCII, EBCDIC or equivalent
form by the program that displays the etext (as is
the case, for instance, with most word processors);

[*] You provide, or agree to also provide on request at
no additional cost, fee or expense, a copy of the
etext in its original plain ASCII form (or in EBCDIC
or other equivalent proprietary form).

[2] Honor the etext refund and replacement provisions of this
"Small Print!" statement.

[3] Pay a trademark license fee to the Project of 20% of the
net profits you derive calculated using the method you
already use to calculate your applicable taxes. If you
don't derive profits, no royalty is due. Royalties are
payable to "Project Gutenberg Association/Carnegie-Mellon
University" within the 60 days following each
date you prepare (or were legally required to prepare)
your annual (or equivalent periodic) tax return.

The Project gratefully accepts contributions in money, time,
scanning machines, OCR software, public domain etexts, royalty
free copyright licenses, and every other sort of contribution
you can think of. Money should be paid to "Project Gutenberg
Association / Carnegie-Mellon University".


The Categories

By Aristotle

Translated by E. M. Edghill

Section 1

Part 1

Things are said to be named 'equivocally' when, though they have
a common name, the definition corresponding with the name differs
for each. Thus, a real man and a figure in a picture can both lay
claim to the name 'animal'; yet these are equivocally so named,
for, though they have a common name, the definition corresponding
with the name differs for each. For should any one define in what
sense each is an animal, his definition in the one case will be
appropriate to that case only.

On the other hand, things are said to be named 'univocally' which
have both the name and the definition answering to the name in
common. A man and an ox are both 'animal', and these are
univocally so named, inasmuch as not only the name, but also the
definition, is the same in both cases: for if a man should state
in what sense each is an animal, the statement in the one case
would be identical with that in the other.

Things are said to be named 'derivatively', which derive their
name from some other name, but differ from it in termination.
Thus the grammarian derives his name from the word 'grammar', and
the courageous man from the word 'courage'.

Part 2

Forms of speech are either simple or composite. Examples of the
latter are such expressions as 'the man runs', 'the man wins'; of
the former 'man', 'ox', 'runs', 'wins'.

Of things themselves some are predicable of a subject, and are
never present in a subject. Thus 'man' is predicable of the
individual man, and is never present in a subject.

By being 'present in a subject' I do not mean present as parts
are present in a whole, but being incapable of existence apart
from the said subject.

Some things, again, are present in a subject, but are never
predicable of a subject. For instance, a certain point of
grammatical knowledge is present in the mind, but is not
predicable of any subject; or again, a certain whiteness may be
present in the body (for colour requires a material basis), yet
it is never predicable of anything.

Other things, again, are both predicable of a subject and present
in a subject. Thus while knowledge is present in the human mind,
it is predicable of grammar.

There is, lastly, a class of things which are neither present in
a subject nor predicable of a subject, such as the individual man
or the individual horse. But, to speak more generally, that which
is individual and has the character of a unit is never predicable
of a subject. Yet in some cases there is nothing to prevent such
being present in a subject. Thus a certain point of grammatical
knowledge is present in a subject.

Part 3

When one thing is predicated of another, all that which is
predicable of the predicate will be predicable also of the
subject. Thus, 'man' is predicated of the individual man; but
'animal' is predicated of 'man'; it will, therefore, be
predicable of the individual man also: for the individual man is
both 'man' and 'animal'.

If genera are different and co-ordinate, their differentiae are
themselves different in kind. Take as an instance the genus
'animal' and the genus 'knowledge'. 'With feet', 'two-footed',
'winged', 'aquatic', are differentiae of 'animal'; the species of
knowledge are not distinguished by the same differentiae. One
species of knowledge does not differ from another in being

But where one genus is subordinate to another, there is nothing
to prevent their having the same differentiae: for the greater
class is predicated of the lesser, so that all the differentiae
of the predicate will be differentiae also of the subject.

Part 4

Expressions which are in no way composite signify substance,
quantity, quality, relation, place, time, position, state,
action, or affection. To sketch my meaning roughly, examples of
substance are 'man' or 'the horse', of quantity, such terms as
'two cubits long' or 'three cubits long', of quality, such
attributes as 'white', 'grammatical'. 'Double', 'half',
'greater', fall under the category of relation; 'in a the market
place', 'in the Lyceum', under that of place; 'yesterday', 'last
year', under that of time. 'Lying', 'sitting', are terms
indicating position, 'shod', 'armed', state; 'to lance', 'to
cauterize', action; 'to be lanced', 'to be cauterized',

No one of these terms, in and by itself, involves an affirmation;
it is by the combination of such terms that positive or negative
statements arise. For every assertion must, as is admitted, be
either true or false, whereas expressions which are not in any
way composite such as 'man', 'white', 'runs', 'wins', cannot be
either true or false.

Part 5

Substance, in the truest and primary and most definite sense of
the word, is that which is neither predicable of a subject nor
present in a subject; for instance, the individual man or horse.
But in a secondary sense those things are called substances
within which, as species, the primary substances are included;
also those which, as genera, include the species. For instance,
the individual man is included in the species 'man', and the
genus to which the species belongs is 'animal'; these,
therefore-that is to say, the species 'man' and the genus
'animal,-are termed secondary substances.

It is plain from what has been said that both the name and the
definition of the predicate must be predicable of the subject.
For instance, 'man' is predicted of the individual man. Now in
this case the name of the species man' is applied to the
individual, for we use the term 'man' in describing the
individual; and the definition of 'man' will also be predicated
of the individual man, for the individual man is both man and
animal. Thus, both the name and the definition of the species are
predicable of the individual.

With regard, on the other hand, to those things which are present
in a subject, it is generally the case that neither their name
nor their definition is predicable of that in which they are
present. Though, however, the definition is never predicable,
there is nothing in certain cases to prevent the name being used.
For instance, 'white' being present in a body is predicated of
that in which it is present, for a body is called white: the
definition, however, of the colour white' is never predicable of
the body.

Everything except primary substances is either predicable of a
primary substance or present in a primary substance. This becomes
evident by reference to particular instances which occur.
'Animal' is predicated of the species 'man', therefore of the
individual man, for if there were no individual man of whom it
could be predicated, it could not be predicated of the species
'man' at all. Again, colour is present in body, therefore in
individual bodies, for if there were no individual body in which
it was present, it could not be present in body at all. Thus
everything except primary substances is either predicated of
primary substances, or is present in them, and if these last did
not exist, it would be impossible for anything else to exist.

Of secondary substances, the species is more truly substance than
the genus, being more nearly related to primary substance. For if
any one should render an account of what a primary substance is,
he would render a more instructive account, and one more proper
to the subject, by stating the species than by stating the genus.
Thus, he would give a more instructive account of an individual
man by stating that he was man than by stating that he was
animal, for the former description is peculiar to the individual
in a greater degree, while the latter is too general. Again, the
man who gives an account of the nature of an individual tree will
give a more instructive account by mentioning the species 'tree'
than by mentioning the genus 'plant'.

Moreover, primary substances are most properly called substances
in virtue of the fact that they are the entities which underlie
every. else, and that everything else is either predicated of
them or present in them. Now the same relation which subsists
between primary substance and everything else subsists also
between the species and the genus: for the species is to the
genus as subject is to predicate, since the genus is predicated
of the species, whereas the species cannot be predicated of the
genus. Thus we have a second ground for asserting that the
species is more truly substance than the genus.

Of species themselves, except in the case of such as are genera,
no one is more truly substance than another. We should not give a
more appropriate account of the individual man by stating the
species to which he belonged, than we should of an individual
horse by adopting the same method of definition. In the same way,
of primary substances, no one is more truly substance than
another; an individual man is not more truly substance than an
individual ox.

It is, then, with good reason that of all that remains, when we
exclude primary substances, we concede to species and genera
alone the name 'secondary substance', for these alone of all the
predicates convey a knowledge of primary substance. For it is by
stating the species or the genus that we appropriately define any
individual man; and we shall make our definition more exact by
stating the former than by stating the latter. All other things
that we state, such as that he is white, that he runs, and so on,
are irrelevant to the definition. Thus it is just that these
alone, apart from primary substances, should be called

Further, primary substances are most properly so called, because
they underlie and are the subjects of everything else. Now the
same relation that subsists between primary substance and
everything else subsists also between the species and the genus
to which the primary substance belongs, on the one hand, and
every attribute which is not included within these, on the other.
For these are the subjects of all such. If we call an individual
man 'skilled in grammar', the predicate is applicable also to the
species and to the genus to which he belongs. This law holds good
in all cases.

It is a common characteristic of all sub. stance that it is never
present in a subject. For primary substance is neither present in
a subject nor predicated of a subject; while, with regard to
secondary substances, it is clear from the following arguments
(apart from others) that they are not present in a subject. For
'man' is predicated of the individual man, but is not present in
any subject: for manhood is not present in the individual man. In
the same way, 'animal' is also predicated of the individual man,
but is not present in him. Again, when a thing is present in a
subject, though the name may quite well be applied to that in
which it is present, the definition cannot be applied. Yet of
secondary substances, not only the name, but also the definition,
applies to the subject: we should use both the definition of the
species and that of the genus with reference to the individual
man. Thus substance cannot be present in a subject.

Yet this is not peculiar to substance, for it is also the case
that differentiae cannot be present in subjects. The
characteristics 'terrestrial' and 'two-footed' are predicated of
the species 'man', but not present in it. For they are not in
man. Moreover, the definition of the differentia may be
predicated of that of which the differentia itself is predicated.
For instance, if the characteristic 'terrestrial' is predicated
of the species 'man', the definition also of that characteristic
may be used to form the predicate of the species 'man': for 'man'
is terrestrial.

The fact that the parts of substances appear to be present in the
whole, as in a subject, should not make us apprehensive lest we
should have to admit that such parts are not substances: for in
explaining the phrase 'being present in a subject', we stated'
that we meant 'otherwise than as parts in a whole'.

It is the mark of substances and of differentiae that, in all
propositions of which they form the predicate, they are
predicated univocally. For all such propositions have for their
subject either the individual or the species. It is true that,
inasmuch as primary substance is not predicable of anything, it
can never form the predicate of any proposition. But of secondary
substances, the species is predicated of the individual, the
genus both of the species and of the individual. Similarly the
differentiae are predicated of the species and of the
individuals. Moreover, the definition of the species and that of
the genus are applicable to the primary substance, and that of
the genus to the species. For all that is predicated of the
predicate will be predicated also of the subject. Similarly, the
definition of the differentiae will be applicable to the species
and to the individuals. But it was stated above that the word
'univocal' was applied to those things which had both name and
definition in common. It is, therefore, established that in every
proposition, of which either substance or a differentia forms the
predicate, these are predicated univocally.

All substance appears to signify that which is individual. In the
case of primary substance this is indisputably true, for the
thing is a unit. In the case of secondary substances, when we
speak, for instance, of 'man' or 'animal', our form of speech
gives the impression that we are here also indicating that which
is individual, but the impression is not strictly true; for a
secondary substance is not an individual, but a class with a
certain qualification; for it is not one and single as a primary
substance is; the words 'man', 'animal', are predicable of more
than one subject.

Yet species and genus do not merely indicate quality, like the
term 'white'; 'white' indicates quality and nothing further, but
species and genus determine the quality with reference to a
substance: they signify substance qualitatively differentiated.
The determinate qualification covers a larger field in the case
of the genus that in that of the species: he who uses the word
'animal' is herein using a word of wider extension than he who
uses the word 'man'.

Another mark of substance is that it has no contrary. What could
be the contrary of any primary substance, such as the individual
man or animal? It has none. Nor can the species or the genus have
a contrary. Yet this characteristic is not peculiar to substance,
but is true of many other things, such as quantity. There is
nothing that forms the contrary of 'two cubits long' or of 'three
cubits long', or of 'ten', or of any such term. A man may contend
that 'much' is the contrary of 'little', or 'great' of 'small',
but of definite quantitative terms no contrary exists.

Substance, again, does not appear to admit of variation of
degree. I do not mean by this that one substance cannot be more
or less truly substance than another, for it has already been
stated' that this is the case; but that no single substance
admits of varying degrees within itself. For instance, one
particular substance, 'man', cannot be more or less man either
than himself at some other time or than some other man. One man
cannot be more man than another, as that which is white may be
more or less white than some other white object, or as that which
is beautiful may be more or less beautiful than some other
beautiful object. The same quality, moreover, is said to subsist
in a thing in varying degrees at different times. A body, being
white, is said to be whiter at one time than it was before, or,
being warm, is said to be warmer or less warm than at some other
time. But substance is not said to be more or less that which it
is: a man is not more truly a man at one time than he was before,
nor is anything, if it is substance, more or less what it is.
Substance, then, does not admit of variation of degree.

The most distinctive mark of substance appears to be that, while
remaining numerically one and the same, it is capable of
admitting contrary qualities. From among things other than
substance, we should find ourselves unable to bring forward any
which possessed this mark. Thus, one and the same colour cannot
be white and black. Nor can the same one action be good and bad:
this law holds good with everything that is not substance. But
one and the selfsame substance, while retaining its identity, is
yet capable of admitting contrary qualities. The same individual
person is at one time white, at another black, at one time warm,
at another cold, at one time good, at another bad. This capacity
is found nowhere else, though it might be maintained that a
statement or opinion was an exception to the rule. The same
statement, it is agreed, can be both true and false. For if the
statement 'he is sitting' is true, yet, when the person in
question has risen, the same statement will be false. The same
applies to opinions. For if any one thinks truly that a person is
sitting, yet, when that person has risen, this same opinion, if
still held, will be false. Yet although this exception may be
allowed, there is, nevertheless, a difference in the manner in
which the thing takes place. It is by themselves changing that
substances admit contrary qualities. It is thus that that which
was hot becomes cold, for it has entered into a different state.
Similarly that which was white becomes black, and that which was
bad good, by a process of change; and in the same way in all
other cases it is by changing that substances are capable of
admitting contrary qualities. But statements and opinions
themselves remain unaltered in all respects: it is by the
alteration in the facts of the case that the contrary quality
comes to be theirs. The statement 'he is sitting' remains
unaltered, but it is at one time true, at another false,
according to circumstances. What has been said of statements
applies also to opinions. Thus, in respect of the manner in which
the thing takes place, it is the peculiar mark of substance that
it should be capable of admitting contrary qualities; for it is
by itself changing that it does so.

If, then, a man should make this exception and contend that
statements and opinions are capable of admitting contrary
qualities, his contention is unsound. For statements and opinions
are said to have this capacity, not because they themselves
undergo modification, but because this modification occurs in the
case of something else. The truth or falsity of a statement
depends on facts, and not on any power on the part of the
statement itself of admitting contrary qualities. In short, there
is nothing which can alter the nature of statements and opinions.
As, then, no change takes place in themselves, these cannot be
said to be capable of admitting contrary qualities.

But it is by reason of the modification which takes place within
the substance itself that a substance is said to be capable of
admitting contrary qualities; for a substance admits within
itself either disease or health, whiteness or blackness. It is in
this sense that it is said to be capable of admitting contrary

To sum up, it is a distinctive mark of substance, that, while
remaining numerically one and the same, it is capable of
admitting contrary qualities, the modification taking place
through a change in the substance itself.

Let these remarks suffice on the subject of substance.

Part 6

Quantity is either discrete or continuous. Moreover, some
quantities are such that each part of the whole has a relative
position to the other parts: others have within them no such
relation of part to part.

Instances of discrete quantities are number and speech; of
continuous, lines, surfaces, solids, and, besides these, time and

In the case of the parts of a number, there is no common boundary
at which they join. For example: two fives make ten, but the two
fives have no common boundary, but are separate; the parts three
and seven also do not join at any boundary. Nor, to generalize,
would it ever be possible in the case of number that there should
be a common boundary among the parts; they are always separate.
Number, therefore, is a discrete quantity.

The same is true of speech. That speech is a quantity is evident:
for it is measured in long and short syllables. I mean here that
speech which is vocal. Moreover, it is a discrete quantity for
its parts have no common boundary. There is no common boundary at
which the syllables join, but each is separate and distinct from
the rest.

A line, on the other hand, is a continuous quantity, for it is
possible to find a common boundary at which its parts join. In
the case of the line, this common boundary is the point; in the
case of the plane, it is the line: for the parts of the plane
have also a common boundary. Similarly you can find a common
boundary in the case of the parts of a solid, namely either a
line or a plane.

Space and time also belong to this class of quantities. Time,
past, present, and future, forms a continuous whole. Space,
likewise, is a continuous quantity; for the parts of a solid
occupy a certain space, and these have a common boundary; it
follows that the parts of space also, which are occupied by the
parts of the solid, have the same common boundary as the parts of
the solid. Thus, not only time, but space also, is a continuous
quantity, for its parts have a common boundary.

Quantities consist either of parts which bear a relative position
each to each, or of parts which do not. The parts of a line bear
a relative position to each other, for each lies somewhere, and
it would be possible to distinguish each, and to state the
position of each on the plane and to explain to what sort of part
among the rest each was contiguous. Similarly the parts of a
plane have position, for it could similarly be stated what was
the position of each and what sort of parts were contiguous. The
same is true with regard to the solid and to space. But it would
be impossible to show that the arts of a number had a relative
position each to each, or a particular position, or to state what
parts were contiguous. Nor could this be done in the case of
time, for none of the parts of time has an abiding existence, and
that which does not abide can hardly have position. It would be
better to say that such parts had a relative order, in virtue of
one being prior to another. Similarly with number: in counting,
'one' is prior to 'two', and 'two' to 'three', and thus the parts
of number may be said to possess a relative order, though it
would be impossible to discover any distinct position for each.
This holds good also in the case of speech. None of its parts has
an abiding existence: when once a syllable is pronounced, it is
not possible to retain it, so that, naturally, as the parts do
not abide, they cannot have position. Thus, some quantities
consist of parts which have position, and some of those which
have not.

Strictly speaking, only the things which I have mentioned belong
to the category of quantity: everything else that is called
quantitative is a quantity in a secondary sense. It is because we
have in mind some one of these quantities, properly so called,
that we apply quantitative terms to other things. We speak of
what is white as large, because the surface over which the white
extends is large; we speak of an action or a process as lengthy,
because the time covered is long; these things cannot in their
own right claim the quantitative epithet. For instance, should
any one explain how long an action was, his statement would be
made in terms of the time taken, to the effect that it lasted a
year, or something of that sort. In the same way, he would
explain the size of a white object in terms of surface, for he
would state the area which it covered. Thus the things already
mentioned, and these alone, are in their intrinsic nature
quantities; nothing else can claim the name in its own right,
but, if at all, only in a secondary sense.

Quantities have no contraries. In the case of definite quantities
this is obvious; thus, there is nothing that is the contrary of
'two cubits long' or of 'three cubits long', or of a surface, or
of any such quantities. A man might, indeed, argue that 'much'
was the contrary of 'little', and 'great' of 'small'. But these
are not quantitative, but relative; things are not great or small
absolutely, they are so called rather as the result of an act of
comparison. For instance, a mountain is called small, a grain
large, in virtue of the fact that the latter is greater than
others of its kind, the former less. Thus there is a reference
here to an external standard, for if the terms 'great' and
'small' were used absolutely, a mountain would never be called
small or a grain large. Again, we say that there are many people
in a village, and few in Athens, although those in the city are
many times as numerous as those in the village: or we say that a
house has many in it, and a theatre few, though those in the
theatre far outnumber those in the house. The terms 'two cubits
long, "three cubits long,' and so on indicate quantity, the terms
'great' and 'small' indicate relation, for they have reference to
an external standard. It is, therefore, plain that these are to
be classed as relative.

Again, whether we define them as quantitative or not, they have
no contraries: for how can there be a contrary of an attribute
which is not to be apprehended in or by itself, but only by
reference to something external? Again, if 'great' and 'small'
are contraries, it will come about that the same subject can
admit contrary qualities at one and the same time, and that
things will themselves be contrary to themselves. For it happens
at times that the same thing is both small and great. For the
same thing may be small in comparison with one thing, and great
in comparison with another, so that the same thing comes to be
both small and great at one and the same time, and is of such a
nature as to admit contrary qualities at one and the same moment.
Yet it was agreed, when substance was being discussed, that
nothing admits contrary qualities at one and the same moment. For
though substance is capable of admitting contrary qualities, yet
no one is at the same time both sick and healthy, nothing is at
the same time both white and black. Nor is there anything which
is qualified in contrary ways at one and the same time.

Moreover, if these were contraries, they would themselves be
contrary to themselves. For if 'great' is the contrary of
'small', and the same thing is both great and small at the same
time, then 'small' or 'great' is the contrary of itself. But this
is impossible. The term 'great', therefore, is not the contrary
of the term 'small', nor 'much' of 'little'. And even though a
man should call these terms not relative but quantitative, they
would not have contraries.

It is in the case of space that quantity most plausibly appears
to admit of a contrary. For men define the term 'above' as the
contrary of 'below', when it is the region at the centre they
mean by 'below'; and this is so, because nothing is farther from
the extremities of the universe than the region at the centre.
Indeed, it seems that in defining contraries of every kind men
have recourse to a spatial metaphor, for they say that those
things are contraries which, within the same class, are separated
by the greatest possible distance.

Quantity does not, it appears, admit of variation of degree. One
thing cannot be two cubits long in a greater degree than another.
Similarly with regard to number: what is 'three' is not more
truly three than what is 'five' is five; nor is one set of three
more truly three than another set. Again, one period of time is
not said to be more truly time than another. Nor is there any
other kind of quantity, of all that have been mentioned, with
regard to which variation of degree can be predicated. The
category of quantity, therefore, does not admit of variation of

The most distinctive mark of quantity is that equality and
inequality are predicated of it. Each of the aforesaid quantities
is said to be equal or unequal. For instance, one solid is said
to be equal or unequal to another; number, too, and time can have
these terms applied to them, indeed can all those kinds of
quantity that have been mentioned.

That which is not a quantity can by no means, it would seem, be
termed equal or unequal to anything else. One particular
disposition or one particular quality, such as whiteness, is by
no means compared with another in terms of equality and
inequality but rather in terms of similarity. Thus it is the
distinctive mark of quantity that it can be called equal and

Section 2

Part 7

Those things are called relative, which, being either said to be
of something else or related to something else, are explained by
reference to that other thing. For instance, the word 'superior'
is explained by reference to something else, for it is
superiority over something else that is meant. Similarly, the
expression 'double' has this external reference, for it is the
double of something else that is meant. So it is with everything
else of this kind. There are, moreover, other relatives, e.g.
habit, disposition, perception, knowledge, and attitude. The
significance of all these is explained by a reference to
something else and in no other way. Thus, a habit is a habit of
something, knowledge is knowledge of something, attitude is the
attitude of something. So it is with all other relatives that
have been mentioned. Those terms, then, are called relative, the
nature of which is explained by reference to something else, the
preposition 'of' or some other preposition being used to indicate
the relation. Thus, one mountain is called great in comparison
with son with another; for the mountain claims this attribute by
comparison with something. Again, that which is called similar
must be similar to something else, and all other such attributes
have this external reference. It is to be noted that lying and
standing and sitting are particular attitudes, but attitude is
itself a relative term. To lie, to stand, to be seated, are not
themselves attitudes, but take their name from the aforesaid

It is possible for relatives to have contraries. Thus virtue has
a contrary, vice, these both being relatives; knowledge, too, has
a contrary, ignorance. But this is not the mark of all relatives;
'double' and 'triple' have no contrary, nor indeed has any such

It also appears that relatives can admit of variation of degree.
For 'like' and 'unlike', 'equal' and 'unequal', have the
modifications 'more' and 'less' applied to them, and each of
these is relative in character: for the terms 'like' and
'unequal' bear 'unequal' bear a reference to something external.
Yet, again, it is not every relative term that admits of
variation of degree. No term such as 'double' admits of this
modification. All relatives have correlatives: by the term
'slave' we mean the slave of a master, by the term 'master', the
master of a slave; by 'double', the double of its hall; by
'half', the half of its double; by 'greater', greater than that
which is less; by 'less,' less than that which is greater.

So it is with every other relative term; but the case we use to
express the correlation differs in some instances. Thus, by
knowledge we mean knowledge the knowable; by the knowable, that
which is to be apprehended by knowledge; by perception,
perception of the perceptible; by the perceptible, that which is
apprehended by perception.

Sometimes, however, reciprocity of correlation does not appear to
exist. This comes about when a blunder is made, and that to which
the relative is related is not accurately stated. If a man states
that a wing is necessarily relative to a bird, the connexion
between these two will not be reciprocal, for it will not be
possible to say that a bird is a bird by reason of its wings. The
reason is that the original statement was inaccurate, for the
wing is not said to be relative to the bird qua bird, since many
creatures besides birds have wings, but qua winged creature. If,
then, the statement is made accurate, the connexion will be
reciprocal, for we can speak of a wing, having reference
necessarily to a winged creature, and of a winged creature as
being such because of its wings.

Occasionally, perhaps, it is necessary to coin words, if no word
exists by which a correlation can adequately be explained. If we
define a rudder as necessarily having reference to a boat, our
definition will not be appropriate, for the rudder does not have
this reference to a boat qua boat, as there are boats which have
no rudders. Thus we cannot use the terms reciprocally, for the
word 'boat' cannot be said to find its explanation in the word
'rudder'. As there is no existing word, our definition would
perhaps be more accurate if we coined some word like 'ruddered'
as the correlative of 'rudder'. If we express ourselves thus
accurately, at any rate the terms are reciprocally connected, for
the 'ruddered' thing is 'ruddered' in virtue of its rudder. So it
is in all other cases. A head will be more accurately defined as
the correlative of that which is 'headed', than as that of an
animal, for the animal does not have a head qua animal, since
many animals have no head.

Thus we may perhaps most easily comprehend that to which a thing
is related, when a name does not exist, if, from that which has a
name, we derive a new name, and apply it to that with which the
first is reciprocally connected, as in the aforesaid instances,
when we derived the word 'winged' from 'wing' and from 'rudder'.

All relatives, then, if properly defined, have a correlative. I
add this condition because, if that to which they are related is
stated as haphazard and not accurately, the two are not found to
be interdependent. Let me state what I mean more clearly. Even in
the case of acknowledged correlatives, and where names exist for
each, there will be no interdependence if one of the two is
denoted, not by that name which expresses the correlative notion,
but by one of irrelevant significance. The term 'slave,' if
defined as related, not to a master, but to a man, or a biped, or
anything of that sort, is not reciprocally connected with that in
relation to which it is defined, for the statement is not exact.
Further, if one thing is said to be correlative with another, and
the terminology used is correct, then, though all irrelevant
attributes should be removed, and only that one attribute left in
virtue of which it was correctly stated to be correlative with
that other, the stated correlation will still exist. If the
correlative of 'the slave' is said to be 'the master', then,
though all irrelevant attributes of the said 'master', such as
'biped', 'receptive of knowledge', 'human', should be removed,
and the attribute 'master' alone left, the stated correlation
existing between him and the slave will remain the same, for it
is of a master that a slave is said to be the slave. On the other
hand, if, of two correlatives, one is not correctly termed, then,
when all other attributes are removed and that alone is left in
virtue of which it was stated to be correlative, the stated
correlation will be found to have disappeared.

For suppose the correlative of 'the slave' should be said to be
'the man', or the correlative of 'the wing"the bird'; if the
attribute 'master' be withdrawn from' the man', the correlation
between 'the man' and 'the slave' will cease to exist, for if the
man is not a master, the slave is not a slave. Similarly, if the
attribute 'winged' be withdrawn from 'the bird', 'the wing' will
no longer be relative; for if the so-called correlative is not
winged, it follows that 'the wing' has no correlative.

Thus it is essential that the correlated terms should be exactly
designated; if there is a name existing, the statement will be
easy; if not, it is doubtless our duty to construct names. When
the terminology is thus correct, it is evident that all
correlatives are interdependent.

Correlatives are thought to come into existence simultaneously.
This is for the most part true, as in the case of the double and
the half. The existence of the half necessitates the existence of
that of which it is a half. Similarly the existence of a master
necessitates the existence of a slave, and that of a slave
implies that of a master; these are merely instances of a general
rule. Moreover, they cancel one another; for if there is no
double it follows that there is no half, and vice versa; this
rule also applies to all such correlatives. Yet it does not
appear to be true in all cases that correlatives come into
existence simultaneously. The object of knowledge would appear to
exist before knowledge itself, for it is usually the case that we
acquire knowledge of objects already existing; it would be
difficult, if not impossible, to find a branch of knowledge the
beginning of the existence of which was contemporaneous with that
of its object.

Again, while the object of knowledge, if it ceases to exist,
cancels at the same time the knowledge which was its correlative,
the converse of this is not true. It is true that if the object
of knowledge does not exist there can be no knowledge: for there
will no longer be anything to know. Yet it is equally true that,
if knowledge of a certain object does not exist, the object may
nevertheless quite well exist. Thus, in the case of the squaring
of the circle, if indeed that process is an object of knowledge,
though it itself exists as an object of knowledge, yet the
knowledge of it has not yet come into existence. Again, if all
animals ceased to exist, there would be no knowledge, but there
might yet be many objects of knowledge.

This is likewise the case with regard to perception: for the
object of perception is, it appears, prior to the act of
perception. If the perceptible is annihilated, perception also
will cease to exist; but the annihilation of perception does not
cancel the existence of the perceptible. For perception implies a
body perceived and a body in which perception takes place. Now if
that which is perceptible is annihilated, it follows that the
body is annihilated, for the body is a perceptible thing; and if
the body does not exist, it follows that perception also ceases
to exist. Thus the annihilation of the perceptible involves that
of perception.

But the annihilation of perception does not involve that of the
perceptible. For if the animal is annihilated, it follows that
perception also is annihilated, but perceptibles such as body,
heat, sweetness, bitterness, and so on, will remain.

Again, perception is generated at the same time as the perceiving
subject, for it comes into existence at the same time as the
animal. But the perceptible surely exists before perception; for
fire and water and such elements, out of which the animal is
itself composed, exist before the animal is an animal at all, and
before perception. Thus it would seem that the perceptible exists
before perception.

It may be questioned whether it is true that no substance is
relative, as seems to be the case, or whether exception is to be
made in the case of certain secondary substances. With regard to
primary substances, it is quite true that there is no such
possibility, for neither wholes nor parts of primary substances
are relative. The individual man or ox is not defined with
reference to something external. Similarly with the parts: a
particular hand or head is not defined as a particular hand or
head of a particular person, but as the hand or head of a
particular person. It is true also, for the most part at least,
in the case of secondary substances; the species 'man' and the
species 'ox' are not defined with reference to anything outside
themselves. Wood, again, is only relative in so far as it is some
one's property, not in so far as it is wood. It is plain, then,
that in the cases mentioned substance is not relative. But with
regard to some secondary substances there is a difference of
opinion; thus, such terms as 'head' and 'hand' are defined with
reference to that of which the things indicated are a part, and
so it comes about that these appear to have a relative character.
Indeed, if our definition of that which is relative was complete,
it is very difficult, if not impossible, to prove that no
substance is relative. If, however, our definition was not
complete, if those things only are properly called relative in
the case of which relation to an external object is a necessary
condition of existence, perhaps some explanation of the dilemma
may be found.

The former definition does indeed apply to all relatives, but the
fact that a thing is explained with reference to something else
does not make it essentially relative.

>From this it is plain that, if a man definitely apprehends a
relative thing, he will also definitely apprehend that to which
it is relative. Indeed this is self-evident: for if a man knows
that some particular thing is relative, assuming that we call
that a relative in the case of which relation to something is a
necessary condition of existence, he knows that also to which it
is related. For if he does not know at all that to which it is
related, he will not know whether or not it is relative. This is
clear, moreover, in particular instances. If a man knows
definitely that such and such a thing is 'double', he will also
forthwith know definitely that of which it is the double. For if
there is nothing definite of which he knows it to be the double,
he does not know at all that it is double. Again, if he knows
that a thing is more beautiful, it follows necessarily that he
will forthwith definitely know that also than which it is more
beautiful. He will not merely know indefinitely that it is more
beautiful than something which is less beautiful, for this would
be supposition, not knowledge. For if he does not know definitely
that than which it is more beautiful, he can no longer claim to
know definitely that it is more beautiful than something else
which is less beautiful: for it might be that nothing was less
beautiful. It is, therefore, evident that if a man apprehends
some relative thing definitely, he necessarily knows that also
definitely to which it is related.

Now the head, the hand, and such things are substances, and it is
possible to know their essential character definitely, but it
does not necessarily follow that we should know that to which
they are related. It is not possible to know forthwith whose head
or hand is meant. Thus these are not relatives, and, this being
the case, it would be true to say that no substance is relative
in character. It is perhaps a difficult matter, in such cases, to
make a positive statement without more exhaustive examination,
but to have raised questions with regard to details is not
without advantage.

Part 8

By 'quality' I mean that in virtue of which people are said to be
such and such.

Quality is a term that is used in many senses. One sort of
quality let us call 'habit' or 'disposition'. Habit differs from
disposition in being more lasting and more firmly established.
The various kinds of knowledge and of virtue are habits, for
knowledge, even when acquired only in a moderate degree, is, it
is agreed, abiding in its character and difficult to displace,
unless some great mental upheaval takes place, through disease or
any such cause. The virtues, also, such as justice,
self-restraint, and so on, are not easily dislodged or dismissed,
so as to give place to vice.

By a disposition, on the other hand, we mean a condition that is
easily changed and quickly gives place to its opposite. Thus,
heat, cold, disease, health, and so on are dispositions. For a
man is disposed in one way or another with reference to these,
but quickly changes, becoming cold instead of warm, ill instead
of well. So it is with all other dispositions also, unless
through lapse of time a disposition has itself become inveterate
and almost impossible to dislodge: in which case we should
perhaps go so far as to call it a habit.

It is evident that men incline to call those conditions habits
which are of a more or less permanent type and difficult to
displace; for those who are not retentive of knowledge, but
volatile, are not said to have such and such a 'habit' as regards
knowledge, yet they are disposed, we may say, either better or
worse, towards knowledge. Thus habit differs from disposition in
this, that while the latter in ephemeral, the former is permanent
and difficult to alter.

Habits are at the same time dispositions, but dispositions are
not necessarily habits. For those who have some specific habit
may be said also, in virtue of that habit, to be thus or thus
disposed; but those who are disposed in some specific way have
not in all cases the corresponding habit.

Another sort of quality is that in virtue of which, for example,
we call men good boxers or runners, or healthy or sickly: in fact
it includes all those terms which refer to inborn capacity or
incapacity. Such things are not predicated of a person in virtue
of his disposition, but in virtue of his inborn capacity or
incapacity to do something with ease or to avoid defeat of any
kind. Persons are called good boxers or good runners, not in
virtue of such and such a disposition, but in virtue of an inborn
capacity to accomplish something with ease. Men are called
healthy in virtue of the inborn capacity of easy resistance to
those unhealthy influences that may ordinarily arise; unhealthy,
in virtue of the lack of this capacity. Similarly with regard to
softness and hardness. Hardness is predicated of a thing because
it has that capacity of resistance which enables it to withstand
disintegration; softness, again, is predicated of a thing by
reason of the lack of that capacity.

A third class within this category is that of affective qualities
and affections. Sweetness, bitterness, sourness, are examples of
this sort of quality, together with all that is akin to these;
heat, moreover, and cold, whiteness, and blackness are affective
qualities. It is evident that these are qualities, for those
things that possess them are themselves said to be such and such
by reason of their presence. Honey is called sweet because it
contains sweetness; the body is called white because it contains
whiteness; and so in all other cases.

The term 'affective quality' is not used as indicating that those
things which admit these qualities are affected in any way. Honey
is not called sweet because it is affected in a specific way, nor
is this what is meant in any other instance. Similarly heat and
cold are called affective qualities, not because those things
which admit them are affected. What is meant is that these said
qualities are capable of producing an 'affection' in the way of
perception. For sweetness has the power of affecting the sense of
taste; heat, that of touch; and so it is with the rest of these

Whiteness and blackness, however, and the other colours, are not
said to be affective qualities in this sense, but -because they
themselves are the results of an affection. It is plain that many
changes of colour take place because of affections. When a man is
ashamed, he blushes; when he is afraid, he becomes pale, and so
on. So true is this, that when a man is by nature liable to such
affections, arising from some concomitance of elements in his
constitution, it is a probable inference that he has the
corresponding complexion of skin. For the same disposition of
bodily elements, which in the former instance was momentarily
present in the case of an access of shame, might be a result of a
man's natural temperament, so as to produce the corresponding
colouring also as a natural characteristic. All conditions,
therefore, of this kind, if caused by certain permanent and
lasting affections, are called affective qualities. For pallor
and duskiness of complexion are called qualities, inasmuch as we
are said to be such and such in virtue of them, not only if they
originate in natural constitution, but also if they come about
through long disease or sunburn, and are difficult to remove, or
indeed remain throughout life. For in the same way we are said to
be such and such because of these.

Those conditions, however, which arise from causes which may
easily be rendered ineffective or speedily removed, are called,
not qualities, but affections: for we are not said to be such
virtue of them. The man who blushes through shame is not said to
be a constitutional blusher, nor is the man who becomes pale
through fear said to be constitutionally pale. He is said rather
to have been affected.

Thus such conditions are called affections, not qualities.
In like manner there are affective qualities and affections of
the soul. That temper with which a man is born and which has its
origin in certain deep-seated affections is called a quality. I
mean such conditions as insanity, irascibility, and so on: for
people are said to be mad or irascible in virtue of these.
Similarly those abnormal psychic states which are not inborn, but
arise from the concomitance of certain other elements, and are
difficult to remove, or altogether permanent, are called
qualities, for in virtue of them men are said to be such and

Those, however, which arise from causes easily rendered
ineffective are called affections, not qualities. Suppose that a
man is irritable when vexed: he is not even spoken of as a
bad-tempered man, when in such circumstances he loses his temper
somewhat, but rather is said to be affected. Such conditions are
therefore termed, not qualities, but affections.

The fourth sort of quality is figure and the shape that belongs
to a thing; and besides this, straightness and curvedness and any
other qualities of this type; each of these defines a thing as
being such and such. Because it is triangular or quadrangular a
thing is said to have a specific character, or again because it
is straight or curved; in fact a thing's shape in every case
gives rise to a qualification of it.

Rarity and density, roughness and smoothness, seem to be terms
indicating quality: yet these, it would appear, really belong to
a class different from that of quality. For it is rather a
certain relative position of the parts composing the thing thus
qualified which, it appears, is indicated by each of these terms.
A thing is dense, owing to the fact that its parts are closely
combined with one another; rare, because there are interstices
between the parts; smooth, because its parts lie, so to speak,
evenly; rough, because some parts project beyond others.

There may be other sorts of quality, but those that are most
properly so called have, we may safely say, been enumerated.

These, then, are qualities, and the things that take their name
from them as derivatives, or are in some other way dependent on
them, are said to be qualified in some specific way. In most,
indeed in almost all cases, the name of that which is qualified
is derived from that of the quality. Thus the terms 'whiteness',
'grammar', 'justice', give us the adjectives 'white',
'grammatical', 'just', and so on.

There are some cases, however, in which, as the quality under
consideration has no name, it is impossible that those possessed
of it should have a name that is derivative. For instance, the
name given to the runner or boxer, who is so called in virtue of
an inborn capacity, is not derived from that of any quality; for
lob those capacities have no name assigned to them. In this, the
inborn capacity is distinct from the science, with reference to
which men are called, e.g. boxers or wrestlers. Such a science is
classed as a disposition; it has a name, and is called 'boxing'
or 'wrestling' as the case may be, and the name given to those
disposed in this way is derived from that of the science.
Sometimes, even though a name exists for the quality, that which
takes its character from the quality has a name that is not a
derivative. For instance, the upright man takes his character
from the possession of the quality of integrity, but the name
given him is not derived from the word 'integrity'. Yet this does
not occur often.

We may therefore state that those things are said to be possessed
of some specific quality which have a name derived from that of
the aforesaid quality, or which are in some other way dependent
on it.

One quality may be the contrary of another; thus justice is the
contrary of injustice, whiteness of blackness, and so on. The
things, also, which are said to be such and such in virtue of
these qualities, may be contrary the one to the other; for that
which is unjust is contrary to that which is just, that which is
white to that which is black. This, however, is not always the
case. Red, yellow, and such colours, though qualities, have no

If one of two contraries is a quality, the other will also be a
quality. This will be evident from particular instances, if we
apply the names used to denote the other categories; for
instance, granted that justice is the contrary of injustice and
justice is a quality, injustice will also be a quality: neither
quantity, nor relation, nor place, nor indeed any other category
but that of quality, will be applicable properly to injustice. So
it is with all other contraries falling under the category of

Qualities admit of variation of degree. Whiteness is predicated
of one thing in a greater or less degree than of another. This is
also the case with reference to justice. Moreover, one and the
same thing may exhibit a quality in a greater degree than it did
before: if a thing is white, it may become whiter.

Though this is generally the case, there are exceptions. For if
we should say that justice admitted of variation of degree,
difficulties might ensue, and this is true with regard to all
those qualities which are dispositions. There are some, indeed,
who dispute the possibility of variation here. They maintain that
justice and health cannot very well admit of variation of degree
themselves, but that people vary in the degree in which they
possess these qualities, and that this is the case with
grammatical learning and all those qualities which are classed as
dispositions. However that may be, it is an incontrovertible fact
that the things which in virtue of these qualities are said to be
what they are vary in the degree in which they possess them; for
one man is said to be better versed in grammar, or more healthy
or just, than another, and so on.

The qualities expressed by the terms 'triangular' and
'quadrangular' do not appear to admit of variation of degree, nor
indeed do any that have to do with figure. For those things to
which the definition of the triangle or circle is applicable are
all equally triangular or circular. Those, on the other hand, to
which the same definition is not applicable, cannot be said to
differ from one another in degree; the square is no more a circle
than the rectangle, for to neither is the definition of the
circle appropriate. In short, if the definition of the term
proposed is not applicable to both objects, they cannot be
compared. Thus it is not all qualities which admit of variation
of degree.

Whereas none of the characteristics I have mentioned are peculiar
to quality, the fact that likeness and unlikeness can be
predicated with reference to quality only, gives to that category
its distinctive feature. One thing is like another only with
reference to that in virtue of which it is such and such; thus
this forms the peculiar mark of quality.

We must not be disturbed because it may be argued that, though
proposing to discuss the category of quality, we have included in
it many relative terms. We did say that habits and dispositions
were relative. In practically all such cases the genus is
relative, the individual not. Thus knowledge, as a genus, is
explained by reference to something else, for we mean a knowledge
of something. But particular branches of knowledge are not thus
explained. The knowledge of grammar is not relative to anything
external, nor is the knowledge of music, but these, if relative
at all, are relative only in virtue of their genera; thus grammar
is said be the knowledge of something, not the grammar of
something; similarly music is the knowledge of something, not the
music of something.

Thus individual branches of knowledge are not relative. And it is
because we possess these individual branches of knowledge that we
are said to be such and such. It is these that we actually
possess: we are called experts because we possess knowledge in
some particular branch. Those particular branches, therefore, of
knowledge, in virtue of which we are sometimes said to be such
and such, are themselves qualities, and are not relative.
Further, if anything should happen to fall within both the
category of quality and that of relation, there would be nothing
extraordinary in classing it under both these heads.

Section 3

Part 9

Action and affection both admit of contraries and also of
variation of degree. Heating is the contrary of cooling, being
heated of being cooled, being glad of being vexed. Thus they
admit of contraries. They also admit of variation of degree: for
it is possible to heat in a greater or less degree; also to be
heated in a greater or less degree. Thus action and affection
also admit of variation of degree. So much, then, is stated with
regard to these categories.

We spoke, moreover, of the category of position when we were
dealing with that of relation, and stated that such terms derived
their names from those of the corresponding attitudes.

As for the rest, time, place, state, since they are easily
intelligible, I say no more about them than was said at the
beginning, that in the category of state are included such states
as 'shod', 'armed', in that of place 'in the Lyceum' and so on,
as was explained before.

Part 10

The proposed categories have, then, been adequately dealt with.
We must next explain the various senses in which the term
'opposite' is used. Things are said to be opposed in four senses:
(i) as correlatives to one another, (ii) as contraries to one
another, (iii) as privatives to positives, (iv) as affirmatives
to negatives.

Let me sketch my meaning in outline. An instance of the use of
the word 'opposite' with reference to correlatives is afforded by
the expressions 'double' and 'half'; with reference to contraries
by 'bad' and 'good'. Opposites in the sense of 'privatives' and
'positives' are' blindness' and 'sight'; in the sense of
affirmatives and negatives, the propositions 'he sits', 'he does
not sit'.

(i) Pairs of opposites which fall under the category of relation
are explained by a reference of the one to the other, the
reference being indicated by the preposition 'of' or by some
other preposition. Thus, double is a relative term, for that
which is double is explained as the double of something.
Knowledge, again, is the opposite of the thing known, in the same
sense; and the thing known also is explained by its relation to
its opposite, knowledge. For the thing known is explained as that
which is known by something, that is, by knowledge. Such things,
then, as are opposite the one to the other in the sense of being
correlatives are explained by a reference of the one to the

(ii) Pairs of opposites which are contraries are not in any way
interdependent, but are contrary the one to the other. The good
is not spoken of as the good of the bad, but as the contrary of
the bad, nor is white spoken of as the white of the black, but as
the contrary of the black. These two types of opposition are
therefore distinct. Those contraries which are such that the
subjects in which they are naturally present, or of which they
are predicated, must necessarily contain either the one or the
other of them, have no intermediate, but those in the case of
which no such necessity obtains, always have an intermediate.
Thus disease and health are naturally present in the body of an
animal, and it is necessary that either the one or the other
should be present in the body of an animal. Odd and even, again,
are predicated of number, and it is necessary that the one or the
other should be present in numbers. Now there is no intermediate
between the terms of either of these two pairs. On the other
hand, in those contraries with regard to which no such necessity
obtains, we find an intermediate. Blackness and whiteness are
naturally present in the body, but it is not necessary that
either the one or the other should be present in the body,
inasmuch as it is not true to say that everybody must be white or
black. Badness and goodness, again, are predicated of man, and of
many other things, but it is not necessary that either the one
quality or the other should be present in that of which they are
predicated: it is not true to say that everything that may be
good or bad must be either good or bad. These pairs of contraries
have intermediates: the intermediates between white and black are
grey, sallow, and all the other colours that come between; the
intermediate between good and bad is that which is neither the
one nor the other.

Some intermediate qualities have names, such as grey and sallow
and all the other colours that come between white and black; in
other cases, however, it is not easy to name the intermediate,
but we must define it as that which is not either extreme, as in
the case of that which is neither good nor bad, neither just nor

(iii) 'privatives' and 'Positives' have reference to the same
subject. Thus, sight and blindness have reference to the eye. It
is a universal rule that each of a pair of opposites of this type
has reference to that to which the particular 'positive' is
natural. We say that that is capable of some particular faculty
or possession has suffered privation when the faculty or
possession in question is in no way present in that in which, and
at the time at which, it should naturally be present. We do not
call that toothless which has not teeth, or that blind which has
not sight, but rather that which has not teeth or sight at the
time when by nature it should. For there are some creatures which
from birth are without sight, or without teeth, but these are not
called toothless or blind.

To be without some faculty or to possess it is not the same as
the corresponding 'privative' or 'positive'. 'Sight' is a
'positive', 'blindness' a 'privative', but 'to possess sight' is
not equivalent to 'sight', 'to be blind' is not equivalent to
'blindness'. Blindness is a 'privative', to be blind is to be in
a state of privation, but is not a 'privative'. Moreover, if
'blindness' were equivalent to 'being blind', both would be
predicated of the same subject; but though a man is said to be
blind, he is by no means said to be blindness.

To be in a state of 'possession' is, it appears, the opposite of
being in a state of 'privation', just as 'positives' and
'privatives' themselves are opposite. There is the same type of
antithesis in both cases; for just as blindness is opposed to
sight, so is being blind opposed to having sight.

That which is affirmed or denied is not itself affirmation or
denial. By 'affirmation' we mean an affirmative proposition, by
'denial' a negative. Now, those facts which form the matter of
the affirmation or denial are not propositions; yet these two are
said to be opposed in the same sense as the affirmation and
denial, for in this case also the type of antithesis is the same.
For as the affirmation is opposed to the denial, as in the two
propositions 'he sits', 'he does not sit', so also the fact which
constitutes the matter of the proposition in one case is opposed
to that in the other, his sitting, that is to say, to his not

It is evident that 'positives' and 'privatives' are not opposed
each to each in the same sense as relatives. The one is not
explained by reference to the other; sight is not sight of
blindness, nor is any other preposition used to indicate the
relation. Similarly blindness is not said to be blindness of
sight, but rather, privation of sight. Relatives, moreover,
reciprocate; if blindness, therefore, were a relative, there
would be a reciprocity of relation between it and that with which
it was correlative. But this is not the case. Sight is not called
the sight of blindness.

That those terms which fall under the heads of 'positives' and
'privatives' are not opposed each to each as contraries, either,
is plain from the following facts: Of a pair of contraries such
that they have no intermediate, one or the other must needs be
present in the subject in which they naturally subsist, or of
which they are predicated; for it is those, as we proved,' in the
case of which this necessity obtains, that have no intermediate.
Moreover, we cited health and disease, odd and even, as
instances. But those contraries which have an intermediate are
not subject to any such necessity. It is not necessary that every
substance, receptive of such qualities, should be either black or
white, cold or hot, for something intermediate between these
contraries may very well be present in the subject. We proved,
moreover, that those contraries have an intermediate in the case
of which the said necessity does not obtain. Yet when one of the
two contraries is a constitutive property of the subject, as it
is a constitutive property of fire to be hot, of snow to be
white, it is necessary determinately that one of the two
contraries, not one or the other, should be present in the
subject; for fire cannot be cold, or snow black. Thus, it is not
the case here that one of the two must needs be present in every
subject receptive of these qualities, but only in that subject of
which the one forms a constitutive property. Moreover, in such
cases it is one member of the pair determinately, and not either
the one or the other, which must be present.

In the case of 'positives' and 'privatives', on the other hand,
neither of the aforesaid statements holds good. For it is not
necessary that a subject receptive of the qualities should always
have either the one or the other; that which has not yet advanced
to the state when sight is natural is not said either to be blind
or to see. Thus 'positives' and 'privatives' do not belong to
that class of contraries which consists of those which have no
intermediate. On the other hand, they do not belong either to
that class which consists of contraries which have an
intermediate. For under certain conditions it is necessary that
either the one or the other should form part of the constitution
of every appropriate subject. For when a thing has reached the
stage when it is by nature capable of sight, it will be said
either to see or to be blind, and that in an indeterminate sense,
signifying that the capacity may be either present or absent; for
it is not necessary either that it should see or that it should
be blind, but that it should be either in the one state or in the
other. Yet in the case of those contraries which have an
intermediate we found that it was never necessary that either the
one or the other should be present in every appropriate subject,
but only that in certain subjects one of the pair should be
present, and that in a determinate sense. It is, therefore, plain
that 'positives' and 'privatives' are not opposed each to each in
either of the senses in which contraries are opposed.

Again, in the case of contraries, it is possible that there
should be changes from either into the other, while the subject
retains its identity, unless indeed one of the contraries is a
constitutive property of that subject, as heat is of fire. For it
is possible that that that which is healthy should become
diseased, that which is white, black, that which is cold, hot,
that which is good, bad, that which is bad, good. The bad man, if
he is being brought into a better way of life and thought, may
make some advance, however slight, and if he should once improve,
even ever so little, it is plain that he might change completely,
or at any rate make very great progress; for a man becomes more
and more easily moved to virtue, however small the improvement
was at first. It is, therefore, natural to suppose that he will
make yet greater progress than he has made in the past; and as
this process goes on, it will change him completely and establish
him in the contrary state, provided he is not hindered by lack of
time. In the case of 'positives' and 'privatives', however,
change in both directions is impossible. There may be a change
from possession to privation, but not from privation to
possession. The man who has become blind does not regain his
sight; the man who has become bald does not regain his hair; the
man who has lost his teeth does not grow a new set. (iv)
Statements opposed as affirmation and negation belong manifestly
to a class which is distinct, for in this case, and in this case
only, it is necessary for the one opposite to be true and the
other false.

Neither in the case of contraries, nor in the case of
correlatives, nor in the case of 'positives' and 'privatives', is
it necessary for one to be true and the other false. Health and
disease are contraries: neither of them is true or false.
'Double' and 'half' are opposed to each other as correlatives:
neither of them is true or false. The case is the same, of
course, with regard to 'positives' and 'privatives' such as
'sight' and 'blindness'. In short, where there is no sort of
combination of words, truth and falsity have no place, and all
the opposites we have mentioned so far consist of simple words.

At the same time, when the words which enter into opposed
statements are contraries, these, more than any other set of
opposites, would seem to claim this characteristic. 'Socrates is
ill' is the contrary of 'Socrates is well', but not even of such
composite expressions is it true to say that one of the pair must
always be true and the other false. For if Socrates exists, one
will be true and the other false, but if he does not exist, both
will be false; for neither 'Socrates is ill' nor 'Socrates is
well' is true, if Socrates does not exist at all.

In the case of 'positives' and 'privatives', if the subject does
not exist at all, neither proposition is true, but even if the
subject exists, it is not always the fact that one is true and
the other false. For 'Socrates has sight' is the opposite of
'Socrates is blind' in the sense of the word 'opposite' which
applies to possession and privation. Now if Socrates exists, it
is not necessary that one should be true and the other false, for
when he is not yet able to acquire the power of vision, both are
false, as also if Socrates is altogether non-existent.

But in the case of affirmation and negation, whether the subject
exists or not, one is always false and the other true. For
manifestly, if Socrates exists, one of the two propositions
'Socrates is ill', 'Socrates is not ill', is true, and the other
false. This is likewise the case if he does not exist; for if he
does not exist, to say that he is ill is false, to say that he is
not ill is true. Thus it is in the case of those opposites only,
which are opposite in the sense in which the term is used with
reference to affirmation and negation, that the rule holds good,
that one of the pair must be true and the other false.

Part 11

That the contrary of a good is an evil is shown by induction: the
contrary of health is disease, of courage, cowardice, and so on.
But the contrary of an evil is sometimes a good, sometimes an
evil. For defect, which is an evil, has excess for its contrary,
this also being an evil, and the mean. which is a good, is
equally the contrary of the one and of the other. It is only in a
few cases, however, that we see instances of this: in most, the
contrary of an evil is a good.

In the case of contraries, it is not always necessary that if one
exists the other should also exist: for if all become healthy
there will be health and no disease, and again, if everything
turns white, there will be white, but no black. Again, since the
fact that Socrates is ill is the contrary of the fact that
Socrates is well, and two contrary conditions cannot both obtain
in one and the same individual at the same time, both these
contraries could not exist at once: for if that Socrates was well
was a fact, then that Socrates was ill could not possibly be one.

It is plain that contrary attributes must needs be present in
subjects which belong to the same species or genus. Disease and
health require as their subject the body of an animal; white and
black require a body, without further qualification; justice and
injustice require as their subject the human soul.

Moreover, it is necessary that pairs of contraries should in all
cases either belong to the same genus or belong to contrary
genera or be themselves genera. White and black belong to the
same genus, colour; justice and injustice, to contrary genera,
virtue and vice; while good and evil do not belong to genera, but
are themselves actual genera, with terms under them.

Part 12

There are four senses in which one thing can be said to be
'prior' to another. Primarily and most properly the term has
reference to time: in this sense the word is used to indicate
that one thing is older or more ancient than another, for the
expressions 'older' and 'more ancient' imply greater length of

Secondly, one thing is said to be 'prior' to another when the
sequence of their being cannot be reversed. In this sense 'one'
is 'prior' to 'two'. For if 'two' exists, it follows directly
that 'one' must exist, but if 'one' exists, it does not follow
necessarily that 'two' exists: thus the sequence subsisting
cannot be reversed. It is agreed, then, that when the sequence of
two things cannot be reversed, then that one on which the other
depends is called 'prior' to that other.

In the third place, the term 'prior' is used with reference to
any order, as in the case of science and of oratory. For in
sciences which use demonstration there is that which is prior and
that which is posterior in order; in geometry, the elements are
prior to the propositions; in reading and writing, the letters of
the alphabet are prior to the syllables. Similarly, in the case
of speeches, the exordium is prior in order to the narrative.

Besides these senses of the word, there is a fourth. That which
is better and more honourable is said to have a natural priority.
In common parlance men speak of those whom they honour and love
as 'coming first' with them. This sense of the word is perhaps
the most far-fetched.

Such, then, are the different senses in which the term 'prior' is

Yet it would seem that besides those mentioned there is yet
another. For in those things, the being of each of which implies
that of the other, that which is in any way the cause may
reasonably be said to be by nature 'prior' to the effect. It is
plain that there are instances of this. The fact of the being of
a man carries with it the truth of the proposition that he is,
and the implication is reciprocal: for if a man is, the
proposition wherein we allege that he is true, and conversely, if
the proposition wherein we allege that he is true, then he is.
The true proposition, however, is in no way the cause of the
being of the man, but the fact of the man's being does seem
somehow to be the cause of the truth of the proposition, for the
truth or falsity of the proposition depends on the fact of the
man's being or not being.

Thus the word 'prior' may be used in five senses.

Part 13

The term 'simultaneous' is primarily and most appropriately
applied to those things the genesis of the one of which is
simultaneous with that of the other; for in such cases neither is
prior or posterior to the other. Such things are said to be
simultaneous in point of time. Those things, again, are
'simultaneous' in point of nature, the being of each of which
involves that of the other, while at the same time neither is the
cause of the other's being. This is the case with regard to the
double and the half, for these are reciprocally dependent, since,
if there is a double, there is also a half, and if there is a
half, there is also a double, while at the same time neither is
the cause of the being of the other.

Again, those species which are distinguished one from another and
opposed one to another within the same genus are said to be
'simultaneous' in nature. I mean those species which are
distinguished each from each by one and the same method of
division. Thus the 'winged' species is simultaneous with the
'terrestrial' and the 'water' species. These are distinguished
within the same genus, and are opposed each to each, for the
genus 'animal' has the 'winged', the 'terrestrial', and the
'water' species, and no one of these is prior or posterior to
another; on the contrary, all such things appear to be
'simultaneous' in nature. Each of these also, the terrestrial,
the winged, and the water species, can be divided again into
subspecies. Those species, then, also will be 'simultaneous'
point of nature, which, belonging to the same genus, are
distinguished each from each by one and the same method of

But genera are prior to species, for the sequence of their being
cannot be reversed. If there is the species 'water-animal', there
will be the genus 'animal', but granted the being of the genus
'animal', it does not follow necessarily that there will be the
species 'water-animal'.

Those things, therefore, are said to be 'simultaneous' in nature,
the being of each of which involves that of the other, while at
the same time neither is in any way the cause of the other's
being; those species, also, which are distinguished each from
each and opposed within the same genus. Those things, moreover,
are 'simultaneous' in the unqualified sense of the word which
come into being at the same time.

Part 14

There are six sorts of movement: generation, destruction,
increase, diminution, alteration, and change of place.

It is evident in all but one case that all these sorts of
movement are distinct each from each. Generation is distinct from
destruction, increase and change of place from diminution, and so
on. But in the case of alteration it may be argued that the
process necessarily implies one or other of the other five sorts
of motion. This is not true, for we may say that all affections,
or nearly all, produce in us an alteration which is distinct from
all other sorts of motion, for that which is affected need not
suffer either increase or diminution or any of the other sorts of
motion. Thus alteration is a distinct sort of motion; for, if it
were not, the thing altered would not only be altered, but would
forthwith necessarily suffer increase or diminution or some one
of the other sorts of motion in addition; which as a matter of
fact is not the case. Similarly that which was undergoing the
process of increase or was subject to some other sort of motion
would, if alteration were not a distinct form of motion,
necessarily be subject to alteration also. But there are some
things which undergo increase but yet not alteration. The square,
for instance, if a gnomon is applied to it, undergoes increase
but not alteration, and so it is with all other figures of this
sort. Alteration and increase, therefore, are distinct.

Speaking generally, rest is the contrary of motion. But the
different forms of motion have their own contraries in other
forms; thus destruction is the contrary of generation, diminution
of increase, rest in a place, of change of place. As for this
last, change in the reverse direction would seem to be most truly
its contrary; thus motion upwards is the contrary of motion
downwards and vice versa.

In the case of that sort of motion which yet remains, of those
that have been enumerated, it is not easy to state what is its
contrary. It appears to have no contrary, unless one should
define the contrary here also either as 'rest in its quality' or
as 'change in the direction of the contrary quality', just as we
defined the contrary of change of place either as rest in a place
or as change in the reverse direction. For a thing is altered
when change of quality takes place; therefore either rest in its
quality or change in the direction of the contrary may be called
the contrary of this qualitative form of motion. In this way
becoming white is the contrary of becoming black; there is
alteration in the contrary direction, since a change of a
qualitative nature takes place.

Part 15

The term 'to have' is used in various senses. In the first place
it is used with reference to habit or disposition or any other
quality, for we are said to 'have' a piece of knowledge or a
virtue. Then, again, it has reference to quantity, as, for
instance, in the case of a man's height; for he is said to 'have'
a height of three or four cubits. It is used, moreover, with
regard to apparel, a man being said to 'have' a coat or tunic; or
in respect of something which we have on a part of ourselves, as
a ring on the hand: or in respect of something which is a part of
us, as hand or foot. The term refers also to content, as in the
case of a vessel and wheat, or of a jar and wine; a jar is said
to 'have' wine, and a corn-measure wheat. The expression in such
cases has reference to content. Or it refers to that which has
been acquired; we are said to 'have' a house or a field. A man is
also said to 'have' a wife, and a wife a husband, and this
appears to be the most remote meaning of the term, for by the use
of it we mean simply that the husband lives with the wife.

Other senses of the word might perhaps be found, but the most
ordinary ones have all been enumerated.

End of Project Gutenberg's etext, The Categories, by Aristotle

Udvalgte artikler
Filosofi: Dekonstruktion
Her introduceres dekonstruktionen som er en filosofi Jaques Derrida grundlagde.

Psykologi: Sigmund Freud og psykoanalysen
Her fremlægges psykoanalysen som er en af de væsentligeste psykologiske retninger.

Filosofi: Ludwig Wittgenstein: Fra logik til sprogspilsteori
Her skildres de to meget forskellige filosofiske sprogteorier som Wittgenstein beskæftigede sig med.

Sociologi og psykologi: Introduktion til Pierre Bourdieu
Om begreber og videnskabsteori hos Bourdieu, som i høj grad benyttes indenfor sociologien og psykologien.

Filosofi: Aristoteles logik og metafysik
En gennemgang af Aristoteles filosofi om logik og metafysik.