[
993a]
[30]
The study of Truth is in one sense
difficult, in another easy. This is shown by the fact that whereas no
one person can obtain an adequate grasp of it, we cannot
all fail in the attempt;
[
993b]
[1]
each
thinker makes some statement about the natural world, and as an
individual contributes little or nothing to the inquiry; but a
combination of all conjectures results in something
considerable.Thus in
so far as it seems that Truth is like the proverbial door which no one
can miss,
1 in
this sense our study will be easy; but the fact that we cannot,
although having some grasp of the whole, grasp a particular part,
shows its difficulty. However, since difficulty also can be accounted
for in two ways, its cause may exist not in the objects of our study
but in ourselves:just as
it is with bats' eyes in respect of daylight, so it is with our mental
intelligence in respect of those things which are by nature most
obvious.
It is only fair to be
grateful not only to those whose views we can share but also to those
who have expressed rather superficial opinions. They too have
contributed something; by their preliminary work they have formed our
mental experience.If there
had been no Timotheus,
2 we
should not possess much of our music; and if there had been no
Phrynis,
3 there would have
been no Timotheus. It is just the same in the case of those who have
theorized about reality: we have derived certain views from some of
them, and they in turn were indebted to others.
Moreover, philosophy is rightly called
[20]
a knowledge of Truth. The object of theoretic
knowledge is truth, while that of practical knowledge is action; for
even when they are investigating
how a thing is so,
practical men study not the eternal principle but the relative and
immediate application.But
we cannot know the truth apart from the cause. Now every thing through
which a common quality is communicated to other things is itself of
all those things in the highest degree possessed of that quality (e.g.
fire is hottest, because it is the cause of heat in everything else);
hence that also is most true which causes all subsequent things to be
true.Therefore in
every case the first principles of things must necessarily be true
above everything else—since they are not merely
sometimes true, nor is anything the cause of their
existence, but they are the cause of the existence of other
things,—and so as each thing is in respect of existence, so
it is in respect of truth.
[
994a]
[1]
Moreover, it is obvious that there is some first principle, and that
the causes of things are not infinitely many either in a direct
sequence or in kind. For the material generation of one thing from
another cannot go on in an infinite progression (e.g. flesh from
earth, earth from air, air from fire, and so on without a stop); nor
can the source of motion (e.g. man be moved by air, air by the sun,
the sun by Strife,
4 with no limit
to the series).In the same
way neither can the Final Cause recede to infinity—walking
having health for its object, and health happiness, and happiness
something else: one thing always being done for the sake of
another.And it is
just the same with the Formal Cause. For in the case of all
intermediate terms of a series which are contained between a first and
last term, the prior term is necessarily the cause of those which
follow it; because if we had to say which of the three is the cause,
we should say "the first." At any rate it is not the last term,
because what comes at the end is not the cause of anything. Neither,
again, is the intermediate term, which is only the cause of
one(and it makes no
difference whether there is one intermediate term or several, nor
whether they are infinite or limited in number). But of series which
are infinite in this way, and in general of the infinite, all the
parts are equally intermediate, down to the present moment. Thus if
there is no first term, there is no cause at all.
On the
other hand there can be no infinite progression downwards
[20]
(where there is a beginning in
the upper direction) such that from fire comes water, and from water
earth, and in this way some other kind of thing is always being
produced. There are two senses in which one thing "comes from"
another—apart from that in which one thing is said to come
after another, e.g. the Olympian "from"
5 the Isthmian
games—either as a man comes from a child as it develops, or
as air comes from water.Now we say that a man "comes from" a child in the sense that that
which
has become something comes from that which
is becoming: i.e. the perfect from the imperfect. (For
just as "becoming" is always intermediate between being and not-being,
so is that which is becoming between what is and what is not. The
learner is becoming informed, and that is the meaning of the statement
that the informed person "comes from" the learner.)On the other hand A comes from B in the
sense that water comes from air by the destruction of B. Hence the
former class of process is not reversible
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994b]
[1]
(e.g.
a child cannot come from a man, for the result of the process of
becoming is not the thing which is becoming, but that which exists
after the process is complete. So day comes from early dawn, because
it is after dawn; and hence dawn does not come from day). But the
other class is reversible.In both cases progression to infinity is impossible; for in the
former the intermediate terms must have an end, and in the second the
process is reversible, for the destruction of one member of a pair is
the generation of the other. At the same time the first cause, being
eternal, cannot be destroyed; because, since the process of generation
is not infinite in the upper direction, that cause which first, on its
destruction, became something else, cannot possibly be eternal.
6Further, the Final cause of a
thing is an
end , and is such that it does not happen for
the sake of some thing else, but all other things happen for its sake.
So if there is to be a last term of this kind, the series will not be
infinite; and if there is no such term, there will be no Final cause.
Those who introduce infinity do not realize that they are abolishing
the nature of the Good (although no one would attempt to do anything
if he were not likely to reach some limit);nor would there be any intelligence in the
world, because the man who has intelligence always acts for the sake
of something, and this is a limit, because the
end is a
limit.
Nor again can the Formal
cause be referred back to another fuller definition;for the prior definition is
always closer, and the posterior is not; and where the original
definition does not apply, neither does the subsequent one.
[20]
Further, those who hold such a
view do away with scientific knowledge, for on this view it is
impossible to know anything until one comes to terms which cannot be
analyzed.Understanding, too, is impossible; for how can one conceive of
things which are infinite in this way? It is different in the case of
the line, which, although in respect of divisibility it never stops,
yet cannot be conceived of unless we make a stop (which is why, in
examining an infinite
7 line, one cannot count the
sections).
8Even matter has to be conceived under
the form of something which changes,
9 and there can be nothing which is infinite.
10 In any case the concept of infinity is not
infinite.
11Again, if the
kinds of causes were infinite in
number it would still be
impossible to acquire knowledge; for it is only when we have become
acquainted with the causes that we assume that we know a thing; and we
cannot, in a finite time, go completely through what is additively
infinite.
The effect of a lecture depends upon
the habits of the listener; because we expect the language to which we
are accustomed,
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995a]
[1]
and anything beyond this seems not to
be on the same level, but somewhat strange and unintelligible on
account of its unfamiliarity; for it is the familiar that is
intelligible. The powerful effect of familiarity is clearly shown by
the laws, in which the fanciful and puerile survivals prevail, through
force of habit, against our recognition of them.Thus some people will not accept the
statements of a speaker unless he gives a mathematical proof; others
will not unless he makes use of illustrations; others expect to have a
poet adduced as witness. Again, some require exactness in everything,
while others are annoyed by it, either because they cannot follow the
reasoning or because of its pettiness; for there is something about
exactness which seems to some people to be mean, no less in an
argument than in a business transaction.
Hence one must
have been already trained how to take each kind of argument, because
it is absurd to seek simultaneously for knowledge and for the method
of obtaining it; and neither is easy to acquire. Mathematical accuracy
is not to be demanded in everything, but only in things which do not
contain matter.Hence this
method is not that of natural science, because presumably all nature
is concerned with matter. Hence we should first inquire what nature
is; for in this way it will become clear what the objects of natural
science are [and whether it belongs to one science or more than one to
study the causes
[20]
and
principles of things].
12