 I can only summarize Vasubandhu’s sophisticated mereological arguments. He begins with the assertion that anything that serves as a sensory object must be a whole made up of basic parts, a bare multiplicity of basic parts, or an aggregate. But none of these can work. A whole made up of parts is rejected on the grounds that things are not perceived over and above their parts. This is a well-developed Buddhist Ābhidharmika view, which coheres with the rejection of a self over and above the aggregates. A bare multiplicity of partless parts is rejected on the grounds that separate atoms are not perceived separately. Thus the only sensible option is a grouping of parts—an aggregate—that somehow becomes perceptible by being joined together.