  If material objects or sensa are part of reality, either there is no relation suitable to be a relation of determining correspondence or there are no objects suitable to serve as primary parts of the universe because they could not be individuated prior to standing in such a  relation.[29] One of McTaggart’s arguments for this conclusion has as a premise that objects with spatial properties, such as material objects, always have their natures in virtue of the natures of their parts. But in this case, unless some material objects are such that at each level of their decomposition into proper parts, new qualities sufficient to describe them uniquely are present, no material object could serve as a primary part of the universe. McTaggart then argues that no such qualitative variation is to be found in the actual  world.[30]