A History of Mediaeval Jewish Philosophy

by Isaac Husik

3. Applying these ideas to motion they say that motion is the passage of an atom of matter from one atom of place to the next in an atom of time. It follows from this that one motion is as fast as another; and they explain the apparent variation in speed of different motions, as for example when two bodies cover unequal distances in the same time, by saying that the body covering the smaller distance had more rests in the intervals between the motions. The same thing is true in the flight of an arrow, that there are rests even though the senses do not reveal them. For the senses cannot be trusted. We must follow the reason.

Maimonides's criticism of the atomic theory of matter and motion just described is that it undermines the bases of geometry. The diagonal of a square would be the same length as its side. The properties of commensurability and incommensurability in lines and surfaces, of rational and irrational lines would cease to have any meaning. In fact all that is contained in the tenth book of Euclid would lose its foundation.

4. The atom is made complete by the accidents, without which it cannot be. Every atom created by God, they say, must have accidents, such as color, odor, motion, and so on, except quantity or magnitude, which according to them is not accident. If a substance has an accident, the latter is not attributed to the body as a whole, but is ascribed to every atom of which the body is composed. Thus in a white body every atom is white, in a moving body every atom is in motion, in a living body every atom is alive, and every atom is possessed of sense perception; for life and sense and reason and wisdom are accidents in their opinion like whiteness and blackness.

6. Accident does not last more than one moment of time. When God creates an atom he creates at the same time an accident with it. Atom without accident is impossible. The accident disappears at the end of the moment unless God creates another of the same kind, and then another, and so on, as long as he wants the accident of that kind to continue. If he ceases to create another accident, the substance too disappears.

Their motive in laying down this theory of accidents is in order to destroy the conception that everything has a peculiar nature, of which its qualities and functions are the results. They attribute everything directly to God. God created a particular accident at this moment, and this is the explanation of its being. If God ceases to create it anew the next moment, it will cease to be.

7. All that is not atom is accident, and there is no difference between one kind of accident and another in reference to essentiality. All bodies are composed of similar atoms, which differ only in accidents; and animality and humanity and sensation and reason are all accidents. Hence the difference between the individuals of the same species is the same as that between individuals of different species. The philosophers distinguish between essential forms of things and accidental properties. In this way they would explain, for example, why iron is hard and black, while butter is soft and white. The Mutakallimun deny any such distinction. All forms are accidents. Hence it would follow that there is no intrinsic reason why man rather than the bat should be a rational creature. Everything that is conceivable is possible, except what involves a logical contradiction; and God alone determines at every instant what accident shall combine with a given atom or group of atoms.

8. It follows from the above also that man has no power of agency at all. When we think we are dyeing a garment red, it is not we who are doing it at all. God creates the red color in the garment at the time when we apply the red dye to it. The red dye does not enter the garment, as we think, for an accident is only momentary, and cannot pass beyond the substance in which it is.

What appears to us as the constancy and regularity of nature is nothing more than the will of God. Nor is our knowledge of to-day the same as that of yesterday. Yesterday's is gone and to-day's is created anew. So when a man moves a pen, it is not he who moves it. God creates motion in the hand, and at the same time in the pen. The hand is not the cause of the motion of the pen. In short they deny causation. God is the sole cause.

In respect to human conduct they are divided. The majority, and the Ashariya among them, say that when a person moves a pen, God creates four accidents, no one of which is the cause of the other. They merely exist in succession, but no more. The first accident is the man's will to move the pen; the second, his ability to move it; the third, the motion of the hand; the fourth, the motion of the pen. It follows from this that when a person does anything, God creates in him a will, the ability and the act itself, but the act is not the effect of the ability. The Muʿtazila hold that the ability is the cause of the effect.

9. Impossibility of the Infinite. They hold that the infinite is impossible in any sense, whether actual or potential or accidental. That an actual infinite is impossible is a matter of proof. So it can be and has been proved that the potential infinite is possible. For example extension is infinitely divisible, i. e., potentially. As to the accidental infinite, i. e., an infinity of parts of which each ceases to be as soon as the next appears, this is doubtful. Those who boast of having proved the eternity of the world say that time is infinite, and defend their view against criticism by the claim that the successive parts of time disappear. In the same way these people regard it as possible that an infinite number of accidents have succeeded each other on the universal matter, because here too they are not all present now, the previous having disappeared before the succeeding ones came. The Mutakallimun do not admit of any kind of infinite. They prove it in this way. If past time and the world are infinite, then the number of men who died up to a given point in the past is infinite. The number of men who died up to a point one thousand years before the former is also infinite. But this number is less than the other by the number of men who died during the thousand years between the two starting points. Hence the infinite is larger than the infinite, which is absurd. If the accidental infinite were really impossible the theory of the eternity of the world would be refuted at once. But Alfarabi has shown that the arguments against accidental infinity are invalid.