What is the meaning of the togetherness of the perceiving mind, in that peculiar modification of perceiving which makes it perceive not a star but a tree, and the tree itself, is a problem for philosophy

Psychology is the science of the act of experiencing, and deals with the whole system of such acts as they make up mental life.

An expectation is a future object, recognised as belonging to me.

But unfortunately Locke treated ideas of reflection as if they were another class of objects of contemplation beside ideas of sensation.

In the perception of a tree we can distinguish the act of experiencing, or perceiving, from the thing experienced, or perceived.

It may be added, to prevent misunderstanding, that when I speak of contemplated objects in this last phrase as objects of contemplation, the act of contemplation itself is of course an enjoyment.

Thus the same object may supply a practical perception to one person and a speculative one to another, or the same person may perceive it partly practically and partly speculatively.