a single human being, a single animal, a single tree, or a single dirham is among the matters most familiar to ordinary people and scholars alike, and among the best known to humankind. It is among their most elementary, self-evident truths derived from sense perception: knowledge of number, and that one is half of two.

Thus, if nothing among bodies could be described as one, and people had not perceived bodies—although knowing that one in the abstract is half of two depends upon knowing that one in external reality is half of two, since universal knowledge in the mind is preceded by knowledge of particular things that actually exist—then, if nothing among bodies were one, the mind could not judge that one is half of two. Yet this is among the most elementary self-evident truths, cited as a standard example in reasoning and debate. Thus, his argument that a body cannot be