The Mutakallem said to the philosopher: What is the reason that we find the substance of iron extremely hard and strong, with a dark colour; the substance of cream, on the other hand, extremely soft and white? The philosopher replied as follows: All physical bodies have two kinds of accidents: those which concern their substance, as, e.g., the health and the illness of a man; and those which concern their form, as, e.g., the astonishment and laughter of a man. The substances of compound bodies differ very much in their ultimate form, according to the difference of the forms peculiar to each component substance. Hence the substance of iron has become in its properties the opposite of the substance of cream, and this difference is attended by the difference of accidents. You notice, therefore, hardness in the one, and softness in the other: two accidents, whose difference results from the difference which exists in the forms of the substances; while the darkness and the whiteness are accidents whose divergence corresponds to that of the two substances in their ultimate condition. The Mutakallem refuted this reply by means of his propositions, as I am now going to state:—There does not exist a form which, as you believe, modifies the substance, and thus causes substances to be different from each other; this difference is exclusively effected by the accidents—according to the theory of the Kalâm, which we mentioned in explaining the eighth proposition. He then continued thus: There is no difference between the substance of iron and that of cream; all things are composed of the same kind of atoms.—We explained the view of the Mutakallemim on this point in treating of the first proposition, the logical consequences of which are, as we have shown, the second and the third propositions; they further require the twelfth proposition, in order to establish the theory of atoms. Nor do they admit that any accidents determine the nature of a substance, or predispose it to receive certain other accidents; for, according to their opinion, an accident cannot be the substratum of another accident, as we have shown in explaining the ninth proposition; nor can it have any duration, according to the sixth proposition. When the Mutakallemim have established all that they wish to infer from these propositions, they arrive at the conclusion that the component atoms of cream and of iron are alike.—The relation of each atom to each of the accidents is the same; one atom is not more adapted than another to receive a certain accident; and as a certain atom is not more fitted to move than to rest, so one atom is not more apt than another to receive the accident of life, of reason, of sensation. It is here of no moment whether a thing contains a larger or smaller quantity of atoms, for, according to the view of the Mutakallemim, which we explained in treating of the fifth proposition, every accident [of a thing] exists in each of its atoms.