 Avicenna’s response to this argument against the potentially infinite divisibility of bodies is considered when discussing his theory of  continuity.  Prior to that, his reasons for rejecting atomism must be examined. To start, Avicenna accepts that division with respect to body is of two sorts: physical division and conceptual division. In physical division, there is the actual fragmentation of a body, with the parts of the body becoming physically separated and at a distance from one another. An example would be when one takes a single quantity of water and places part of it in one vessel and the other part in another vessel. Avicenna concedes that it well may be the case that bodies have some physical limit beyond which they no longer can be physically divided and still remain the same sort of body. To provide an example of Avicenna’s point, our quantity of water can be divided as water until one reaches a single water molecule; division beyond that point, while producing hydrogen and oxygen atoms, does not produce smaller particles of water. A single water molecule, then, is physically indivisible as water; it no longer remains as water after any further division. Still, inasmuch as a single water molecule occupies some space, however small, one can conceive of half of that water molecule, and so it is conceptually divisible qua magnitude. Whether there actually are such physically indivisible units, Avicenna insists, requires proof, which I consider when looking at  Avicenna’s elemental theory.  