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.