In the middle ages 205

determination found equally in the water and in

the hydrogen-oxygen. Othei^wise the one could

not change into the other; no transformation of

water into its component parts would occur, but

instead there would be annihilation (of the water)

followed by creation (of the hydrogen-oxygen).

As for the specific principle, this must exist at each

stage of the process as a peculiar and proper factor

whereby the water as such differs from the hydro-

gen-oxygen as such.

With this we come to the theory of primary

matter and substantial form, — so often misunder-

stood. This is really nothing but an application of

the theory of act and potency to the problem of the

transformation of bodies. Primary matter is

the common indeterminate element or substratum,

capable of receiving successively contrary deter-

minations. The substantial form determines this

unformed and potential fundament, and fixes the

being altogether in its individuality and in its spe-

cific mode of existence. Each man, each lion, each

oak, each chemical individual, possesses its form;

that is, its principle of proper perfection. And

the principle of perfection, or of the form which

is immanent in the oak, is not reducible to that

which belongs to the man, or to the molecule of

hydrogen.

All that belongs to the perfection of a being (its

existence, its unity, its activities) is more closely

related to the form, while all that belongs to its

206 PHILOSOPHY AND CIVILIZATION

imperfect state (its indetermination) is more close-

ly related to the matter, — and especially is this true

of the quantitative extension of corporeal being.

To be extended in space, in divisible quantity, is

an imperfection ; and no really distinct beings could

exist, were it not for the unifying function of

form assembling the scattered elements of extend-

ed matter. No doctrine really better explains the

mixture of perfection and imperfection, of good

and evil, which are rooted in the depths of all

corporeal being.

Thus the corporeal world mounts stage by stage

from one species to another, nature passes from one

step to another, from one species to another, fol-

lowing a certain definite order. Nature changes

water into hydrogen and oxygen, but it does not

change a pebble into a lion ; nor can one make a saw

out of wool. It evolves bodies according to affini-

ties and successive progressions, the deciphering of

which is the mission of the particular sciences, which

we can know only by patient observation. If there

are any saltations in nature, they are never capri-

cious. In every corporeal substance, at every stage

and at every instant, the germs of the substantial

states are found which are to be born out of it.

This is the meaning of the formula repeated by the

scholastics, "that primary matter contains poten-

tially, or in promise, the series of forms in which it

must dress and redress itself, in the course of its

becoming." To ask, as some do, where the forms