But though cognition is not an element of mental action, nor even in any real sense of the word an aspect of it, the distinction of cognition and conation has if properly defined a definite value.

Desire then is the invasion of the whole self by the wish, which, as it invades, sets going more and more of the psychical processes; but at the same time, so long as it remains desire, does not succeed in getting possession of the self.

An object is not first imagined or thought about and then expected or willed, but in being actively expected it is imagined as future and in being willed it is thought.

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.

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

The thing of which the act of perception is the perception is experienced as something not mental.

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.