Various Works
in the same class with the things that in one way or another are
called 'the same' in view of unity of species. For all such things
seem to be of one family and to resemble one another. For the reaon
why all water is said to be specifically the same as all other water
is because of a certain likeness it bears to it, and the only
difference in the case of water drawn from the same spring is this,
that the likeness is more emphatic: that is why we do not
distinguish it from the things that in one way or another are called
'the same' in view of unity of species. It is generally supposed
that the term 'the same' is most used in a sense agreed on by every
one when applied to what is numerically one. But even so, it is apt to
be rendered in more than one sense; its most literal and primary use
is found whenever the sameness is rendered in reference to an
alternative name or definition, as when a cloak is said to be the same
as a doublet, or an animal that walks on two feet is said to be the
same as a man: a second sense is when it is rendered in reference to a
property, as when what can acquire knowledge is called the same as a
man, and what naturally travels upward the same as fire: while a third
use is found when it is rendered in reference to some term drawn
from Accident, as when the creature who is sitting, or who is musical,
is called the same as Socrates. For all these uses mean to signify
numerical unity. That what I have just said is true may be best seen
where one form of appellation is substituted for another. For often
when we give the order to call one of the people who are sitting down,
indicating him by name, we change our description, whenever the person
to whom we give the order happens not to understand us; he will, we
think, understand better from some accidental feature; so we bid him
call to us 'the man who is sitting' or 'who is conversing over
there'-clearly supposing ourselves to be indicating the same object by
its name and by its accident.
8
Of 'sameness' then, as has been said,' three senses are to be
distinguished. Now one way to confirm that the elements mentioned
above are those out of which and through which and to which
arguments proceed, is by induction: for if any one were to survey
propositions and problems one by one, it would be seen that each was
formed either from the definition of something or from its property or
from its genus or from its accident. Another way to confirm it is
through reasoning. For every predicate of a subject must of
necessity be either convertible with its subject or not: and if it
is convertible, it would be its definition or property, for if it
signifies the essence, it is the definition; if not, it is a property:
for this was what a property is, viz. what is predicated
convertibly, but does not signify the essence. If, on the other
hand, it is not predicated convertibly of the thing, it either is or
is not one of the terms contained in the definition of the subject:
and if it be one of those terms, then it will be the genus or the
differentia, inasmuch as the definition consists of genus and
differentiae; whereas, if it be not one of those terms, clearly it
would be an accident, for accident was said' to be what belongs as
an attribute to a subject without being either its definition or its
genus or a property.
9
Next, then, we must distinguish between the classes of predicates in
which the four orders in question are found. These are ten in
number: Essence, Quantity, Quality, Relation, Place, Time, Position,
State, Activity, Passivity. For the accident and genus and property
and definition of anything will always be in one of these
categories: for all the propositions found through these signify
either something's essence or its quality or quantity or some one of
the other types of predicate. It is clear, too, on the face of it that
the man who signifies something's essence signifies sometimes a
substance, sometimes a quality, sometimes some one of the other
types of predicate. For when man is set before him and he says that
what is set there is 'a man' or 'an animal', he states its essence and
signifies a substance; but when a white colour is set before him and
he says that what is set there is 'white' or is 'a colour', he
states its essence and signifies a quality. Likewise, also, if a
magnitude of a cubit be set before him and he says that what is set
there is a magnitude of a cubit, he will be describing its essence and
signifying a quantity. Likewise, also, in the other cases: for each of
these kinds of predicate, if either it be asserted of itself, or its
genus be asserted of it, signifies an essence: if, on the other
hand, one kind of predicate is asserted of another kind, it does not
signify an essence, but a quantity or a quality or one of the other
kinds of predicate. Such, then, and so many, are the subjects on which
arguments take place, and the materials with which they start. How
we are to acquire them, and by what means we are to become well
supplied with them, falls next to be told.
10
First, then, a definition must be given of a 'dialectical
proposition' and a 'dialectical problem'. For it is not every
proposition nor yet every problem that is to be set down as
dialectical: for no one in his senses would make a proposition of what
no one holds, nor yet make a problem of what is obvious to everybody
or to most people: for the latter admits of no doubt, while to the
former no one would assent. Now a dialectical proposition consists
in asking something that is held by all men or by most men or by the
philosophers, i.e. either by all, or by most, or by the most notable
of these, provided it be not contrary to the general opinion; for a
man would probably assent to the view of the philosophers, if it be
not contrary to the opinions of most men. Dialectical propositions
also include views which are like those generally accepted; also
propositions which contradict the contraries of opinions that are
taken to be generally accepted, and also all opinions that are in
accordance with the recognized arts. Thus, supposing it to be a
general opinion that the knowledge of contraries is the same, it might
probably pass for a general opinion also that the perception of
contraries is the same: also, supposing it to be a general opinion
that there is but one single science of grammar, it might pass for a
general opinion that there is but one science of flute-playing as
well, whereas, if it be a general opinion that there is more than
one science of grammar, it might pass for a general opinion that there
is more than one science of flute-playing as well: for all these
seem to be alike and akin. Likewise, also, propositions
contradicting the contraries of general opinions will pass as
general opinions: for if it be a general opinion that one ought to
do good to one's friends, it will also be a general opinion that one
ought not to do them har
m. Here, that one ought to do harm to one's
friends is contrary to the general view, and that one ought not to
do them harm is the contradictory of that contrary. Likewise also,
if one ought to do good to one's friends, one ought not to do good
to one's enemies: this too is the contradictory of the view contrary
to the general view; the contrary being that one ought to do good to
one's enemies. Likewise, also, in other cases. Also, on comparison, it
will look like a general opinion that the contrary predicate belongs
to the contrary subject: e.g. if one ought to do good to one's
friends, one ought also to do evil to one's enemies. it might appear
also as if doing good to one's friends were a contrary to doing evil
to one's enemies: but whether this is or is not so in reality as
well will be stated in the course of the discussion upon contraries.
Clearly also, all opinions that are in accordance with the arts are
dialectical propositions; for people are likely to assent to the views
held by those who have made a study of these things, e.g. on a
question of medicine they will agree with the doctor, and on a
question of geometry with the geometrician; and likewise also in other
cases.
11
A dialectical problem is a subject of inquiry that contributes
either to choice and avoidance, or to truth and knowledge, and that
either by itself, or as a help to the solution of some other such
problem. It must, moreover, be something on which either people hold
no opinion either way, or the masses hold a contrary opinion to the
philosophers, or the philosophers to the masses, or each of them among
themselves. For some problems it is useful to know with a view to
choice or avoidance, e.g. whether pleasure is to be chosen or not,
while some it is useful to know merely with a view to knowledge,
e.g. whether the universe is eternal or not: others, again, are not
useful in and by themselves for either of these purposes, but yet help
us in regard to some such problems; for there are many things which we
do not wish to know in and by themselves, but for the sake of other
things, in order that through them we may come to know something else.
Problems also include questions in regard to which reasonings conflict
(the difficulty then being whether so-and so is so or not, there being
convincing arguments for both views); others also in regard to which
we have no argument because they are so vast, and we find it difficult
to give our reasons, e.g. the question whether the universe is eternal
or no: for into questions of that kind too it is possible to inquire.
Problems, then, and propositions are to be defined as aforesaid. A
'thesis' is a supposition of some eminent philosopher that conflicts
with the general opinion; e.g. the view that contradiction is
impossible, as Antisthenes said; or the view of Heraclitus that all
things are in motion; or that Being is one, as Melissus says: for to
take notice when any ordinary person expresses views contrary to men's
usual opinions would be silly. Or it may be a view about which we have
a reasoned theory contrary to men's usual opinions, e.g. the view
maintained by the sophists that what is need not in every case
either have come to be or be eternal: for a musician who is a
grammarian 'is' so without ever having 'come to be' so, or being so
eternally. For even if a man does not accept this view, he might do so
on the ground that it is reasonable.
Now a 'thesis' also is a problem, though a problem is not always a
thesis, inasmuch as some problems are such that we have no opinion
about them either way. That a thesis, however, also forms a problem,
is clear: for it follows of necessity from what has been said that
either the mass of men disagree with the philosophers about the
thesis, or that the one or the other class disagree among
themselves, seeing that the thesis is a supposition in conflict with
general opinion. Practically all dialectical problems indeed are now
called 'theses'. But it should make no difference whichever
description is used; for our object in thus distinguishing them has
not been to create a terminology, but to recognize what differences
happen to be found between them.
Not every problem, nor every thesis, should be examined, but only
one which might puzzle one of those who need argument, not
punishment or perception. For people who are puzzled to know whether
one ought to honour the gods and love one's parents or not need
punishment, while those who are puzzled to know whether snow is
white or not need perception. The subjects should not border too
closely upon the sphere of demonstration, nor yet be too far removed
from it: for the former cases admit of no doubt, while the latter
involve difficulties too great for the art of the trainer.
12
Having drawn these definitions, we must distinguish how many species
there are of dialectical arguments. There is on the one hand
Induction, on the other Reasoning. Now what reasoning is has been said
before: induction is a passage from individuals to universals, e.g.
the argument that supposing the skilled pilot is the most effective,
and likewise the skilled charioteer, then in general the skilled man
is the best at his particular task. Induction is the more convincing
and clear: it is more readily learnt by the use of the senses, and
is applicable generally to the mass of men, though reasoning is more
forcible and effective against contradictious people.
13
The classes, then, of things about which, and of things out of
which, arguments are constructed, are to be distinguished in the way
we have said before. The means whereby we are to become well
supplied with reasonings are four: (1) the securing of propositions;
(2) the power to distinguish in how many senses particular
expression is used; (3) the discovery of the differences of things;
(4) the investigation of likeness. The last three, as well, are in a
certain sense propositions: for it is possible to make a proposition
corresponding to each of them, e.g. (1) 'The desirable may mean either
the honourable or the pleasant or the expedient'; and (2) Sensation
differs from knowledge in that the latter may be recovered again after
it has been lost, while the former cannot'; and (3) The relation of
the healthy to health is like that of the vigorous to vigour'. The
first proposition depends upon the use of one term in several
senses, the second upon the differences of things, the third upon
their likenesses.
14
Propositions should be selected in a number of ways corresponding to
the number of distinctions drawn in regard to the proposition: thus
one may first take in hand the opinions held by all or by most men
or by the philosophers, i.e. by all, or most, or the most notable of
them; or opinions contrary to those that seem to be generally held;
and, again, all opinions that are in accordance with the arts. We must
make propositions also of the contradictories of opinions con
trary
to those that seem to be generally held, as was laid down before. It
is useful also to make them by selecting not only those opinions
that actually are accepted, but also those that are like these, e.g.
'The perception of contraries is the same'-the knowledge of them being
so-and 'we see by admission of something into ourselves, not by an
emission'; for so it is, too, in the case of the other senses; for
in hearing we admit something into ourselves; we do not emit; and we
taste in the same way. Likewise also in the other cases. Moreover, all
statements that seem to be true in all or in most cases, should be
taken as a principle or accepted position; for they are posited by
those who do not also see what exception there may be. We should
select also from the written handbooks of argument, and should draw up
sketch-lists of them upon each several kind of subject, putting them
down under separate headings, e.g. 'On Good', or 'On Life'-and that
'On Good' should deal with every form of good, beginning with the
category of essence. In the margin, too, one should indicate also
the opinions of individual thinkers, e.g. 'Empedocles said that the
elements of bodies were four': for any one might assent to the
saying of some generally accepted authority.
Of propositions and problems there are-to comprehend the matter in
outline-three divisions: for some are ethical propositions, some are
on natural philosophy, while some are logical. Propositions such as
the following are ethical, e.g. 'Ought one rather to obey one's
parents or the laws, if they disagree?'; such as this are logical,
e.g. 'Is the knowledge of opposites the same or not?'; while such as
this are on natural philosophy, e.g. 'Is the universe eternal or not?'
Likewise also with problems. The nature of each of the aforesaid kinds
of proposition is not easily rendered in a definition, but we have
to try to recognize each of them by means of the familiarity
attained through induction, examining them in the light of the
illustrations given above.
For purposes of philosophy we must treat of these things according