When we spoke of substance as one of the categories we were using it in
a secondary sense. We meant by substances "horse," "man," and the rest
of the "real kinds" which we find in Nature, and try to reproduce in a
scientific classification. In this sense of the word "substances" are a
special class of _predicates_, as when we affirm of Plato that he is a
man, or of Bucephalus that he is a horse. But in the primary sense a
substance means an absolutely individual thing, "_this_ man," or "_this_
horse." We may therefore define primary substances from the logician's
point of view by saying that they can be only subjects of predication,
never predicates. Or again, it is peculiar to substances, that while
remaining numerically one a substance admits of incompatible
determinations, as Socrates, remaining one and the same Socrates, is
successively young and old. This is not true of "qualities," "actions,"
and the rest. The same colour cannot be first white and then black; the
same act cannot be first bad and then good. Thus we may say that
individual substances are the fixed and permanent factors in the world
of mutability, the invariants of existence. Processes go on in them,
they run the gamut of changes from birth to decay, processes take place
_among_ them, they act on and are acted on by one another, they
fluctuate in their qualities and their magnitude, but so long as a
substance exists it remains numerically one and the same throughout all
these changes. Their existence is the first and most fundamental
condition of the existence of the universe, since they are the bearers
of all qualities, the terms of all relations, and the agents and
patients in all interaction.
The point to note is that Aristotle begins his investigation into the
structure of What Is and the causes by which it is produced by starting
from the existence of individual things belonging to the physical order
and perceived by the senses. About any such thing we may ask two
questions, (1) into what constituent factors can it be logically
analysed? (2) and how has it come to exhibit the character which our
analysis shows it to have? The answer to these questions will appear
from a consideration of two standing antitheses which run through
Aristotle's philosophy, the contrast between Matter and Form, and that
between Potential and Actual, followed by a recapitulation of his
doctrine of the Four Causes, or four senses of the word Cause.
*Matter and Form*.--Consider any completely developed individual thing,
whether it is the product of human manufacture, as a copper bowl, or of
natural reproduction, as an oak-tree or a horse. We shall see at once
that the bowl is like other articles made of the same metal,
candlesticks, coal-vases, in being made of the same stuff, and unlike
them in having the special shape or structure which renders it fit for
being used as a bowl and not for holding a candle or containing coals.
So a botanist or a chemist will tell you that the constituent tissues of
an oak or horse, or the chemical elements out of which these tissues are
built up are of the same kind as those of an ash or an ox, but the oak
differs from the ash or the horse from the ox in characteristic
structure. We see thus that in any individual thing we can distinguish
two components, the stuff of which it consists--which may be identical
in kind with the stuff of which things of a very different kind
consist--and the structural law of formation or arrangement which is
peculiar to the "special" kind of thing under consideration. In the
actual individual thing these two are inseparably united; they do not
exist side by side, as chemists say the atoms of hydrogen and oxygen do
in a drop of water; the law of organisation or structure is manifested
in and through the copper, or the various tissues of the living body.
Aristotle expresses this by saying that you can distinguish two aspects
in an individual, its Matter, (_hyle, materia_) and its Form (_eidos,
forma_). The individual is the matter as organised in accord with a
determinate principle of structure, the form. Of these terms, the
former, _hyle_ (_materia_, matter) means literally timber, and more
specifically ship's timbers, and his selection of it to mean what is
most exactly rendered by our own word "stuff" may perhaps be due to a
reminiscence of an old Pythagorean fancy which looked on the universe as
a ship. The word for form is the same as Plato's, and its philosophical
uses are closely connected with its mathematical sense, "regular
figure," also a Pythagorean technicality which still survives in certain
stereotyped phrases in Euclid. Aristotle extends the analysis into
Matter and Form by analogy beyond the range of individual substances to
everything in which we can distinguish a relatively indeterminate
"somewhat" and a law or type of order and arrangement giving it
determination. Thus if you consider the relatively fixed or "formed"
character of a man in adult life, we may look upon this character as
produced out of the "raw material" of tendencies and dispositions, which
have received a specific development along definite lines, according to
the kind of training to which the mind has been subjected in the
"formative" period of its growth. We may therefore speak of native
disposition as the matter or stuff of which character is made, and the
practical problem of education is to devise a system of training which
shall impress on this matter precisely the form required if the grown
man is to be a good citizen of a good state. Since a man's character
itself is not a substance but a complex of habits or fixed ways of
reacting upon suggestions coming from the world around him, this is a
good instance of the extension of the antithesis of Matter and Form
beyond the category of substance. We see then that Matter in the
Aristotelian sense must not be confounded with body; the relatively
undetermined factor which receives completer determination by the
structural law or Form is Matter, whether it is corporeal or not. This
comes out with particular clearness in the metaphysical interpretation
put on the logical process of definition by genus and difference. When
I define any real kind by specifying a higher and wider class of which
it is a sub-kind, and adding the peculiar characteristics which
distinguish the sub-kind under consideration from the other sub-kinds of
the same genus, the genus may be said to stand to the "differences" as
Matter, the relatively indeterminate, to the Form which gives it its
structure.
We further observe that Matter and Form are strictly correlative. The
matter is called so relatively to the form which gives it further
determination. When the words are used in their strictest sense, with
reference to an individual thing, the Form is taken to mean the _last_
determination by which the thing acquires its complete character, and
the Matter is that which has yet to receive this last determination.
Thus in the case of a copper globe, the spherical figure is said to be
its Form, the copper its material. In the case of the human body, the
Matter is the various tissues, muscles, bones, skin, &c. But each of
these things which are counted as belonging to the Matter of the globe
or the human body has, according to Aristotle, a development behind it.
Copper is not an "element" but a specific combination of "elements," and
the same thing is even more true of the highly elaborate tissues of the
living body. Thus what is Matter relatively to the globe or living body
is Matter already determined by Form if we consider it relatively to its
own constituents. The so-called "elements" of Empedocles, earth, water,
air, fire, are the matter of all chemical compounds, the Form of each
compound being its specific law of composition; the immediate or
"proximate" Matter of the tissues of the animal body is, according to
Aristotle's biology, the "superfluous" blood of the female parent, out
of which the various tissues in the offspring are developed, and the
Matter of this blood is in turn the various substances which are taken
into the body of the parent as food and converted by assimilation into
blood. Their Matter, once more, is the earth, air, fire, and water of
which they are composed. Thus at every stage of a process of manufacture
or growth a fresh Form is superinduced on, or developed within, a Matter
which is already itself a combination of Matter and Form relatively to
the process by which it has itself been originated. Fully thought out,
such a view would lead to the conclusion that in the end the simple
ultimate matter of all individual things is one and the same throughout
the universe, and has absolutely no definite structure at all. The
introduction of Form or determinate structure of any kind would then
have to be thought of as coming from an outside source, since
structureless Matter cannot be supposed to give itself all sorts of
specific determinations, as has been demonstrated in our own times by
the collapse of the "Synthetic Philosophy." Aristotle avoids the
difficulty by holding that "pure Matter" is a creation of our thought.
In actual fact the crudest form in which matter is found is that of the
"elements." Since the transmutability of the "elements" is an
indispensable tenet in Aristotle's Physics, we cannot avoid regarding
earth, water, fire air as themselves determinations by specific Form of
a still simpler Matter, though this "prime Matter" "all alone, before a
rag of Form is on," is never to be found existing in its simplicity.[#]
[#] _Hudibras_, Pt. 1, Canto 1, 560.
"He had First Matter seen undressed;
He took her naked all alone,
Before one rag of Form was on."
*The Potential and the Actual*.--So far we have been looking at the
analysis of the individual thing, as the current jargon puts it,
statically; we have arrived at the antithesis of Matter and Form by
contrasting an unfinished condition of anything with its finished
condition. But we may study the same contrast dynamically, with special
reference to the process of making or growth by which the relatively
undetermined or unfinished becomes determined or finished. The contrast
of Matter with Form then passes into the contrast between Potentiality
and Actuality. What this antithesis means we can best see from the case
of the growth of a living organism. Consider the embryos of two animals,
or the seeds of two plants. Even a botanist or a physiologist may be
unable to pronounce with certainty on the species to which the germ
submitted to him belongs, and chemical analysis may be equally at a
loss. Even at a later stage of development, the embryo of one
vertebrate animal may be indistinguishable from that of another. Yet it
is certain that one of two originally indistinguishable germs will grow
into an oak and the other into an elm, or one into a chimpanzee and the
other into a man. However indistinguishable, they therefore may be said
to have different latent tendencies or possibilities of development
within them. Hence we may say of a given germ, "though this is not yet
actually an oak, it is potentially an oak," meaning not merely that, if
uninterfered with, it will in time be an oak, but also that by no
interference can it be made to grow into an elm or a beech. So we may
look upon all processes of production or development as processes by
which what at first possessed only the tendency to grow along certain
lines or to be worked up into a certain form, has become actually
endowed with the character to which it possessed the tendency. The
acorn becomes in process of time an actual oak, the baby an actual man,
the copper is made into an actual vase, right education brings out into
active exercise the special capacities of the learner. Hence the
distinction between Matter and Form may also be expressed by saying that
the Matter is the persistent underlying _substratum_ in which the
development of the Form takes place, or that the individual when finally
determined by the Form is the Actuality of which the undeveloped Matter
was the Potentiality. The process of conception, birth, and growth to
maturity in Nature, or of the production of a finished article by the
"arts" whose business it is to "imitate" Nature, may be said to be one
of continuous advance towards the actual embodiment of a Form, or law of
organisation, in a Matter having the latent potentiality of developing
along those special lines. When Aristotle is speaking most strictly he
distinguishes the process by which a Form is realised, which he calls
Energeia, from the manifestation of the realised Form, calling the
latter Entelechy (literally "finished" or "completed" condition).
Often, however, he uses the word Energeia more loosely for the actual
manifestation of the Form itself, and in this he is followed by the
scholastic writers, who render Energeia by _actus_ or _actus purus_.
One presupposition of this process must be specially noted. It is not an
unending process of development of unrealised capacities, but always has
an End in the perfectly simple sense of a last stage. We see this best
in the case of growth. The acorn grows into the sapling and the sapling
into the oak, but there is nothing related to the oak as the oak is to
the sapling. The oak does not grow into something else. The process of
development from potential to actual in this special case comes to an
end with the emergence of the mature oak. In the organic world the end
or last state is recognised by the fact that the organism can now
exercise the power of reproducing its like. This tendency of organic
process to culminate in a last stage of complete maturity is the key to
the treatment of the problem of the "true end" of life in Aristotle's
_Ethics_.
*The Four Causes*.--The conception of the world involved in these
antitheses of Form and Matter, Potential and Actual, finds its fullest
expression in Aristotle's doctrine of the Four Causes or conditions of
the production of things. This doctrine is looked on by Aristotle as
the final solution of the problem which had always been the central one
for Greek philosophy, What are the causes of the world-order? All the
previous philosophies he regards as inadequate attempts to formulate the
answer to this question which is only given completely by his own
system. Hence the doctrine requires to be stated with some fullness.
We may best approach it by starting from the literal meaning of the
Greek terms _aitia_, _aition_, which Aristotle uses to convey the notion
of cause. _Aition_ is properly an adjective used substantially, and
means "that on which the legal responsibility for a given state of
affairs can be laid." Similarly _aitia_, the substantive, means the
"credit" for good or bad, the legal "responsibility," for an act. Now
when we ask, "what is responsible for the fact that such and such a
state of things now exists?" there are four partial answers which may be
given, and each of these corresponds to one of the "causes." A complete
answer requires the enumeration of them all. We may mention (1) the
_matter_ or _material_ cause of the thing, (2) the law according to
which it has grown or developed, the _form_ or _formal_ cause, (3) the
agent with whose initial impulse the development began--the
"starting-point of the process," or, as the later Aristotelians call it,
the _efficient_ cause, (4) the completed result of the whole process,
which is present in the case of human manufacture as a preconceived idea
determining the maker's whole method of handling his material, and in
organic development in Nature as implied in and determining the
successive stages of growth--the _end_ or _final_ cause. If any one of
these had been different, the resultant state of things would also have
been different. Hence all four must be specified in completely
accounting for it. Obvious illustrations can be given from artificial
products of human skill, but it seems clear that it was rather
reflection on the biological process of reproduction and growth which
originally suggested the analysis. Suppose we ask what was requisite in
order that there should be now an oak on a given spot. There must have
been (1) a germ from which the oak has grown, and this germ must have
had the latent tendencies towards development which are characteristic
of oaks. This is the material cause of the oak. (2) This germ must
have followed a definite law of growth; it must have had a tendency to
grow in the way characteristic of oaks and to develop the structure of
an oak, not that of a plane or an ash. This is form or formal cause.
(3) Also the germ of the oak did not come from nowhere; it grew on a
parent oak. The parent oak and its acorn-bearing activity thus
constitute the _efficient_ cause of the present oak. (4) And there must
be a final stage to which the whole process of growth is relative, in
which the germ or sapling is no longer becoming but is an adult oak
bearing fresh acorns. This is the _end_ of the process. One would not
be going far wrong in saying that Aristotle's biological cast of thought
leads him to conceive of this "end" in the case of reproduction as a
sub-conscious purpose, just as the workman's thought of the result to be
attained by his action forms a conscious directing purpose in the case
of manufacture. Both in Nature and in "art" the "form," the "efficient
cause," and the "end" tend to coalesce. Thus in Nature "a man begets a
man," organic beings give birth to other organic beings of the same
kind, or, in the technical language of the Aristotelian theory of
Causation, the efficient cause produces, as the "end" of its action, a
second being having the same "form" as itself, though realised in
different "matter," and numerically distinct from itself. Thus the
efficient cause (_i.e._ the parent) is a "form" realised in matter, and
the "end" is the same "form" realised in other matter. So in "products
of art" the true "source of the process" is the "form" the realisation
of which is the "end" or final cause, only with this difference, that as
efficient cause the "form" exists not in the material but by way of
"idea" or "representation" in the mind of the craftsman. A house does
not produce another house, but the house as existing in "idea" in the
builder's mind sets him at work building, and so produces a
corresponding house in brick or stone. Thus the ultimate opposition is
between the "cause as matter," a passive and inert substratum of change
and development and the "formal" cause which, in the sense just
explained, is one with both the "efficient" or starting-point, and the
"end" or goal of development. It will, of course, be seen that
individual bearers of "forms" are indispensable in the theory; hence the
notion of _activity_ is essential to the causal relation. It is a
relation between things, not between events. Aristotle has no sense of
the word cause corresponding to Mill's conception of a cause as an event
which is the uniform precursor of another event.
Two more remarks may be made in this connection. (1) The prominence of
the notion of "end" gives Aristotle's philosophy a thorough-going
"ideological" character. God and Nature, he tells us, do nothing
aimlessly. We should probably be mistaken if we took this to mean that
"God and Nature" act everywhere with conscious design. The meaning is
rather that every natural process has a last stage in which the "form"
which was to begin with present in the agent or "source of change" is
fully realised in the matter in which the agent has set up the process
of change. The normal thing is _e.g._ for animals to reproduce "their
kind"; if the reproduction is imperfect or distorted, as in monstrous
births, this is an exception due to the occasional presence in "matter"
of imperfections which hinder the course of development, and must be
regarded as "contrary to the normal course of Nature." So hybrid
reproduction is exceptional and "against Nature," and this is shown by
the sterility of hybrids, a sort of lesser monstrosity. Even females,
being "arrested developments," are a sort of still minor deviation from
principle. (2) It may just be mentioned that Aristotle has a
classification of efficient causes under the three heads of Nature,
Intelligence (or Man), and Chance. The difference between Nature and
Man or Intelligence as efficient causes has already been illustrated.
It is that in causation by Nature, such as sexual reproduction, or the
assimilation of nutriment, or the conversion of one element into another
in which Aristotle believed, the form which is superinduced on the
matter by the agent already exists in the agent itself as _its_ form.
The oak springs from a parent oak, the conversion of nutriment into
organic tissue is due to the agency of already existing organic tissue.
In the case of human intelligence or art, the "form" to be superinduced
exists in the agent not as _his_ characteristic form, but by way of
representation, as a contemplated design. The man who builds a house is
not himself a house; the form characteristic of a house is very
different from that characteristic of a man, but it is present in
contemplation to the builder before it is embodied in the actual house.
A word may be added about the third sort of efficient causality,
causation by chance. This is confined to cases which are exceptions
from the general course of Nature, remarkable coincidences. It is what
we may call "simulated purposiveness." When something in human affairs
happens in a way which subserves the achievement of a result but was not
really brought about by any intention to secure the result, we speak of
it as a remarkable coincidence. Thus it would be a coincidence if a man
should be held to ransom by brigands and his best friend should, without
knowing anything of the matter, turn up on the spot with the means of
ransoming him. The events could not have happened more opportunely if
they had been planned, and yet they were not planned but merely fell out
so: and since such a combination of circumstances simulating design is
unusual, it is not proper to say that the events happened "in the course
of Nature." We therefore say it happened by chance. This doctrine of
chance has its significance for mediaeval Ethics. In an age when the
Protestant superstition that worldly success is proof of nearness to God
had not yet been invented, the want of correspondence between men's
"deserts" and their prosperity was accounted for by the view that the
distribution of worldly goods is, as a rule, the work of Fortune or
Chance in the Aristotelian sense; that is, it is due to special
coincidences which may look like deliberate design but are not really
so. (See the elaborate exposition of this in Dante, _Inferno_, vii.
67-97.)
*Motion*.--We have seen that causation, natural or artificial, requires
the production in a certain "matter" of a certain "form" under the
influence of a certain "agent." What is the character of the process
set up by the agent in the matter and culminating in the appearance of
the form? Aristotle answers that it is Motion (_kinesis_). The effect
of the agent on the matter is to set up in it a motion which ends in its
assuming a definite form. The important point to be noted here is that
Aristotle regards this motion as falling wholly within the matter which
is to assume the form. It is not necessary that the agent should itself
be in motion, but only that it should induce motion in something else.
Thus in all cases of intentional action the ultimate efficient cause is
the "idea of the result to be attained," but this idea does not move
about. By its presence to the mind it sets something else (the members
of the body) moving. This conception of an efficient cause which, not
moving itself, by its mere presence induces movement in that to which it
is present, is of the highest importance in Aristotle's theology. Of
course it follows that since the motion by which the transition from
potentiality to actuality is achieved falls wholly within the matter
acted upon, Aristotle is not troubled with any of the questions as to
the way in which motion can be transferred from one body to another
which were so much agitated in the early days of the modern mechanical
interpretation of natural processes. Aristotle's way of conceiving
Nature is thoroughly non-mechanical, and approximates to what would now
be called the ascription of vital or quasi-vital characteristics to the
inorganic. As, in the causality of "art" the mere presence of the
"form" to be embodied in a given material to the mind of the craftsman
brings about and directs the process of manufacture, so in some
analogous fashion the presence of an efficient cause in Nature to that
on which it works is thought of as itself constituting the "efficiency"
of the cause. As Lotze phrases it, things "take note of" one another's
compresence in the universe, or we might say the efficient cause and
that on which it exercises its efficiency are _en rapport_. "Matter" is
sensitive to the presence of the "efficient cause," and in response to
this sensitivity, puts forth successive determinations, expands its
latent tendencies on definite lines.