Thomas Aquinas Quotes

God should not be called an individual substance, since the principal of individuation is matter.

We are assuming that we exist, that there is reality, and that the matter of which we are made is real.

Einstein said, if everything exists as a substance of qualities, and qualities exist only in mind, then all is mind.

Now, the causes being four, it is the business of the student of nature to know about them all, and if he refers his problems back to all of them, he will assign the "why" in the way proper to his science-the matter, the form, the mover, that for the sake of which.

I regard consciousness as fundamental. I regard matter as a derivative of consciousness.

And there must be simple substances, because there are compounds; for the compound is nothing but a collection or aggregatum of simples.

It is not possible for form to do without matter because it is not separable, nor can matter itself be purged of form.

There is nothing in the universe but matter.

The whole universe is composed of name and form. Whatever we see is either a compound of name and form, or simply name with form which is a mental image.

[Quantity is the fundamental feature of things,] the 'primarium accidens substantiae,' ...prior to the other categories.

Aristotle's metaphysics, roughly speaking, may be described as Plato diluted by common sense. He is difficult because Plato and common sense do not mix easily.

Metaphysical problems about "mind" versus "matter" arise only from epistemological confusions.

Whatever form it has, it [matter] will be disposed to receive another form; it never leaves off moving and casting off the form which it has in order to receive another. ...It is therefore clear that all corruption, destruction, or defect comes from matter.

I should . . . prefer swallowing one incomprehensibility rather than two. It requires one effort only to admit the single incomprehensibility of matter endowed with thought, and two to believe, first that of an existence called spirit, of which we have neither evidence nor idea, and then secondly how that spirit, which has neither extension nor solidity, can put material organs into motion.

Nonbeing must in some sense be, otherwise what is it that there is not? This tangled doctrine might be nicknamed Plato's beard; historically it has proved tough, frequently dulling the edge of Occam's razor.

The soul is the form of the body

The monad, of which we shall speak here, is nothing but a simple substance which enters into compounds; simple, that is to say, without parts.

Among the great things which are found among us the existence of Nothing is the greatest.

But if men would give heed to the nature of substance they would doubt less concerning the Proposition that Existence appertains to the nature of substance: rather they would reckon it an axiom above all others, and hold it among common opinions. For then by substance they would understand that which is in itself, and through itself is conceived, or rather that whose knowledge does not depend on the knowledge of any other thing.

Being is the soul of every concept, of every judgment and of every reasoning.

It is clear that there is some difference between ends: some ends are energeia [energy], while others are products which are additional to the energeia.

Philosophy ... must not bargain away anything of the emphatic concept of truth.

Every generation has to find their own heroes.

Brain deals exclusively with the physical, and mind exclusively with the metaphysical.

What is reasonable is real; that which is real is reasonable.