like a womb for a child—namely, tinder, touchwood and similar materials that catch fire more readily than others—just as a woman conceives by a man. The fire may fail to catch, just as a woman may fail to conceive; and no spark may be produced, just as no semen may be discharged. Fire is not of the same kind as the two fire-making sticks; rather, it is generated from them, just as an animal is generated from water and clay. Animals are of two kinds: those produced through reproduction, such as humans, livestock and other creatures created from two parents; and those generated otherwise, such as creatures that arise from fruit and vinegar, lice generated from the dirt on human skin, mice, fleas and other creatures created from water and earth.
People have disagreed concerning the animals, plants, minerals, rain, fire kindled with fire-making sticks, and other things that Allah creates: are the very entities of these bodies brought into existence, with one kind transformed into another—as semen is transformed into a clinging clot and then a lump of flesh—or is it only accidents that come into being, while the entities themselves, which are substances, remain with different attributes through the four states He brings about in them: aggregation, separation, motion and rest? There are two views.
Some hold that bodies are composed either of individual, indivisible substances, as many speculative theologians maintain, or of infinitely many substances, as is reported of al-Nazzām.