for Muslims are the witnesses set over mankind, testifying to realities as they truly are by virtue of the guidance, light, and knowledge Allah has granted them. Through that gift He preferred them above the rest of the nations who themselves were guided by the light of the divine scriptures—so what, then, of the nations that possessed none of that light?
Aristotle realized the error of his predecessors and demonstrated the invalidity of the views of Plato and Pythagoras. Ibn Sīnā and others like him followed Aristotle’s lead, observing that philosophy, in its first intention, was still unripe, its point of departure being reflection on the natural sciences. Hence they imagined that the abstract universals conceived by the human mind exist externally. Yet Aristotle and his followers did not rid themselves of all this misguidance: they affirmed the existence of matter outside the mind, but asserted that an essence cannot exist without individual instances, nor matter without form.
We have discussed all of this at length elsewhere. Our purpose here is merely to draw attention to the substance of this objector’s argument: the premise he has cited rests on that very principle—and even so, he has offered no proof for it. At this juncture we shall content ourselves with outright denial, for a bare claim warrants nothing more than denial. We therefore say to him: we do not concede that anything existent outside the mind possesses an essence other than the very, tangible entity that is perceived outside the mind. How, then, could such an essence be receptive to its existence, or the cause of its existence, or could one of its attributes be the cause of another attribute?
On the contrary, we know with indubitable certainty that within any given, self-subsisting being there are not two independent substances—one animal and the other rational. The very substance described as animal is the same substance described as rational. Consequently, every existent, in the reality that is its essence, its selfhood, its very being, is nothing other than itself; nor is it anything apart from this concrete, particular entity perceived by the senses. No other reality accompanies it besides this concrete, particular individual—neither something universal nor something additional that is merely particular.