A monad gains the ability to apperceive by reflectively representing its own perceptions, which it can only do if it has access to a wide variety of distinct and detailed perceptions of a part of the universe, from its point-of-view. Therefore, the point of view of this monad must include organized perceptions of other monads, in such a relation that the apperceiving monad can integrate these perceptions. Note that none of this implies a set of causal relations amongst these monads, although a situation like this is certainly correlative with the body and sense apparatus of an animal. In Leibniz's model, the physical system is the correlate of this set of perceptual relations as seen from the perspective of another subject.
Toward an Elegant Panpsychism: Leibniz's "Monadology" and the Combination Problem
Patrick Mellor