In his ever-present work of creation, God gives being to many different particular things and
many different kinds of things. He gives being to visible things like cats and dogs, grass, flowers,
trees, sun and moon, human beings and a host of other things. He also gives being to invisible
things above us like the angels, and invisible things below us like sub-atomic particles.
The evidence of common sense tells us that things of our everyday experience are real
and come in many different natural kinds. Whenever we are talking about a particular thing in nature
that is real, and belongs to a specific natural kind, and is irreducible to anything else,
Aristotle and Aquinas call that particular thing a primary substance. In his work of creation,
God is now giving being to a world of a bewildering variety of primary substances.
Some are material, others immaterial. Some are very big, others medium in size,
and still others very small. What all the primary substances have in common,
and what makes each of them irreducible to anything else, is their substantial form.
Thanks to their substantial forms, constituting many primary substances large, medium, and small,
it cannot be said that what is really real is just particles and forces and that everything else is
reducible to them. Rather, what is really real is you and me, cats and dogs, grass, flowers, trees,
and perhaps particles and forces too depending on how one understands them. Nature is a wonderful
array of mysteries existing at many levels of perfection all displaying the wisdom of God.
God gives each really existing thing or primary substance its substantial form,
and its substantial form is what makes a thing to be what it is, to be one, and to be intelligible.
Let us consider each of these points. First, substantial form makes a thing to be what
it is. The substantial form of a cat, for example, is what makes it to be a cat. A cat is an orderly
whole with different biological systems such as a cardiac system, digestive system, nervous system,
and more. In order for those systems to work, the cat needs parts, not just any kind of parts,
but certain kinds of parts. The cardiac system needs a heart and blood, the digestive system
needs a throat and stomach, and the nervous system needs a brain and spine and more. The
substantial form of the cat is the order of the whole organism, but that order includes the order
of all the subsystems, all the parts of all the subsystems, and all the parts of all the parts.
But the substantial form is not just the order or plan of a thing. It is also the inner source of
all the activities or operations of the whole, all the systems, and all the parts. Substantial form
is the source of the beating heart, the firing nerves, and the active digestion going on.
The substantial form fixes the developmental sequence of the whole cat from beginning to end,
and the substantial form is the very being-at-work of the cat, driving it on its development
to its end, that is, to full development and operation in the optimal state of flourishing.
All of this goes into the little expression that substantial form makes a thing to be what it is.
But let us focus on one point in particular.
The substantial form of the whole cat is what accounts for the parts,
and the parts of the parts all the way down, and the activities or operations of the parts.
Philosophers have come to call this top down or whole-to-part explanation. The claim is that in a
primary substance the form of the whole accounts for the parts, not the parts for the whole.
Those who say the parts account for the whole tell a bottom up explanation of what makes the cat to
be what it is, and bottom up stories often imply that the cat does not really exist. It is not a
primary substance but reducible to something else. It is just particles or physical things and forces
at work invisibly in the cat, and the form of a cat is really an accidental form of the particles.
When bottom up explanations are absolutized across all phenomena, one implication is that all the
things of ordinary experience and daily life are not really real. They are not primary substances.
What is really real – we often hear – is rather invisible things and forces at the
bottom of the world, and science alone can tell us what those are.
But is that true? Does science obligate us to say that? No. Modern science does not rule out
substantial form in the things of daily life or top down interpretations of scientific
principles and findings. In fact, in many ways it is more consistent with science
to say that a great many ordinary things have substantial forms and the forms of wholes account
for their parts and processes rather than the other way around. What is really real is you,
and me, and our cats, dogs, and similar things. Science does not deny that, but welcomes it.
It explains better, for example, a wide array of emergent properties and avoids undermining
the general reliability of ordinary experience and common sense on which all science is based.
Second, substantial form makes a thing to be one in a special way. Let us compare a cat with a car.
A car has many parts, but when the whole car loses its form as a car, the parts continue to be what
they are. The leather in the seat continues to be leather, the glass in the windshield
continues to be glass, and the rubber in the tires continues to be rubber. A cat too has many parts,
but when the whole cat loses its form as a cat, the parts do not continue to be what
they are. The tail is no longer a tail, the eyes no longer eyes, and the heart no longer a heart.
A severed finger, Aristotle says, is not a finger except equivocally so called.
What he means is that although we call a severed finger by the name of finger, it is not really a
finger. Because a finger is essentially a living member of living body, and the severed thing is
neither a member nor living. So too with all the parts of a cat that has lost its substantial form.
Though we may call them a tail, eyes, and a heart for a while, they are really different in kind
from what they were in the cat. They no longer participate in a living organism,
and therefore are no longer living in any way. We can see now that the form of a car is accidental,
and makes its parts to be coordinated, but not to be what each one is. The form of a cat
is substantial, and makes its parts to be not only coordinated, but to be what each one is.
Substantial form gives primary substances an irreducible unity, and because of substantial form
all the parts of primary substances are essentially participants
of a whole that is really real. Finally, substantial form makes a thing
to be intelligible. Understanding essentially consists of reading the forms of things in nature.
It is like when a person is engrossed in reading a novel. The reader becomes the book, so to speak,
and is mentally living the story. Human beings who study the things of nature become engrossed
in reading the book of nature, and mentally live the very forms of things in nature. If thought is
one thing, and things are another, then is there really knowledge? Aristotle realized that for
there to be knowledge of a thing, the form in the thing and the form in our mind must be one and the
same form. And that is what knowledge is – oneness of mind and things according to their forms.
In his goodness, God gives being to a world of things have substantial forms
so that we may know the forms of things in nature,
and ultimately, so that we might know him, and love him, and marvel at his wisdom forever.
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