is admitted by the intellect as possible; e.g., that the terrestrial globe should become the all-encompassing sphere, or that this sphere should become the terrestrial globe; reason does not find here an impossibility; or that the sphere of fire should move towards the centre, and the sphere of earth towards the circumference. Human intellect does not perceive any reason why a body should be in a certain place instead of being in another. In the same manner they say that reason admits the possibility that an existing being should be larger or smaller than it really is, or that it should be different in form and position from what it really is; e.g., a man might have the height of a mountain, might have several heads, and fly in the air; or an elephant might be as small as an insect, or an insect as huge as an elephant. This method of admitting possibilities is applied to the whole Universe. Whenever they affirm that a thing belongs to this class of admitted possibilities, they say that it can have this form, and that it is also possible that it be found differently, and that the one form is not more possible than the other; but they do not ask whether the reality confirms their assumption. They say that the thing which exists with certain constant and permanent forms, dimensions, and properties, only follows the direction of habit, just as the king generally rides on horseback through the streets of the city, and is never found departing from this habit; but reason does not find it impossible that he should walk on foot through the place: there is no doubt that he may do so, and this possibility is fully admitted by the intellect. Similarly, earth moves towards the centre, fire turns away from the centre; fire causes heat, water causes cold, in accordance with a certain habit; but it is logically not impossible that a deviation from this habit should occur, namely, that fire should cause cold, move downward, and still be fire; that the water should cause heat, move upward, and still be water. On this foundation their whole fabric is constructed. They admit, however, the impossibility of two opposite properties coexisting at the same time in one substance. This is impossible; reason would not admit this possibility. Again, reason does not admit the possibility of a substance existing without an accident, or an accident existing without a substance. a possibility admitted by some of the Mutakallemim. It is also impossible that a substance should become an accident, that an accident should become a substance, or that one substance should penetrate another. They admit that reason rejects all these things as impossible. It is perfectly true that no notion whatever can be formed of those things which they describe as impossible; whilst a notion can be formed of those things which they consider as possible. The philosophers object to this method. and say, You call a thing impossible because it cannot be imagined, or possible because it can be imagined: and thus you consider as possible that which is found possible by imagination, not by the intellect, consequently you determine that a thing is necessary, possible, or impossible in some instances, by the aid of the imagination--not by the intellect--and in other instances by the ordinary common sense. as Abu Nasr says in speaking of that which the Mutakallemim call intellect. It is clear that they describe as possible that which can be imagined, whether the reality correspond to it or not, and as impossible that which cannot be imagined. This proposition can only be established by the nine aforementioned propositions, and no doubt these were exclusively required for the support of this
