 Some will deny GK1. What does seem obviously possible (and easily imaginable) for there to be certain kinds of infinite descent. But infinite descent need not be mereological. For instance, it does seem possible for there to be objects that can be divided into two halves, and whose halves can in turn be divided into two halves, and so on. But it is controversial whether the fact that o can be divided into two halves, h1 and h2, entails that o is not simple. One might deny that h1 and h2 exist at all before the division: they are brought into existence when o is divided and, a fortiori, are not parts of o prior to division. Or one might concede that, prior to division, h1 and h2 exist and are partially colocated with o, but deny that they are thereby parts of  o.[74]