Change, for Aristotle, can take
place in many different categories. Local motion, as noted, is change in the
category of place. Change in the category of quantity is growth (or shrinkage),
and change in the category of quality (e.g., of colour) is what Aristotle calls
“alteration.” Change in the category of substance, however—a change of one kind
of thing into another—is very special. When a substance undergoes a change of
quantity or quality, the same substance remains throughout. But does anything
persist when one kind of thing turns into another? Aristotle’s answer is
yes: matter. He says,
“By matter, I mean what in itself is neither of any kind nor of any size
nor describable by any of the categories of being. For it is something of which
all these things are predicated, and therefore its essence is different from
that of all the predicates.”
An entity that is not of any kind,
size, or shape and of which nothing at all can be said may seem highly
mysterious, but this is not what Aristotle has in mind. His ultimate matter (he
sometimes calls it “prime matter”) is not in itself of any kind. It is not in
itself of any particular size, because it can grow or shrink; it is not in
itself water or steam, because it is both of these in turn. But this does not
mean that there is any time at which it is not of any size or any time at which
it is neither water nor steam nor anything else.
Ordinary life provides many examples
of pieces of matter changing from one kind to another. A bottle containing a
pint of cream may be found, after shaking, to contain not cream but butter. The
stuff that comes out of the bottle is the same as the stuff that went into it;
nothing has been added and nothing taken away. But what comes out is different
in kind from what went in. It is from cases such as this that the Aristotelian
notion of matter is derived.
Form
Although Aristotle’s system makes
room for forms, they differ significantly from Forms as Plato conceived them.
For Aristotle, the form of a particular thing is not separate (chorista) from
the thing itself—any form is the form of some thing. In Aristotle’s physics,
form is always paired with matter, and the paradigm examples of forms are those
of material substances.
Aristotle distinguishes between
“substantial” and “accidental” forms. A substantial form is a second substance
(species or kind) considered as a universal; the predicate human, for example,
is universal as well as substantial. Thus, Socrates is human may be described
as predicating a second substance of a first substance (Socrates) or as
predicating a substantial form of a first substance. Whereas substantial forms
correspond to the category of substance, accidental forms correspond to
categories other than substance; they are nonsubstantial categories considered
as universals. Socrates is wise, for example, may be described as predicating a
quality (wise) of a first substance or as predicating an accidental form of a
first substance. Aristotle calls such forms “accidental” because they may
undergo change, or be gained or lost, without thereby changing the first
substance into something else or causing it to cease to exist. Substantial
forms, in contrast, cannot be gained or lost without changing the nature of the
substance of which they are predicated. In the propositions above, wise is an
accidental form and human a substantial form; Socrates could survive the loss
of the former but not the loss of the latter.
When a thing comes into being,
neither its matter nor its form is created. When one manufactures a bronze
sphere, for example, what comes into existence is not the bronze or the
spherical shape but the shaped bronze. Similarly in the case of the human
Socrates. But the fact that the forms of things are not created does not mean
that they must exist independently of matter, outside space and time, as Plato
maintained. The bronze sphere derives its shape not from an ideal Sphere but
from its maker, who introduces form into the appropriate matter in the process
of his work. Likewise, Socrates’ humanity derives not from an ideal Human but
from his parents, who introduce form into the appropriate matter when they
conceive him.
Thus, Aristotle reverses the
question asked by Plato: “What is it that two human beings have in common that
makes them both human?” He asks instead, “What makes two human beings two
humans rather than one?” And his answer is that what makes Socrates distinct
from his friend Callias is not their substantial form, which is the same, nor
their accidental forms, which may be the same or different, but their matter.
Matter, not form, is the principle of individuation.
No comments:
Post a Comment