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.
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 expectation is a future object, recognised as belonging to me.
It is more difficult to designate this form of conation on its practical side by a satisfactory name.
Both expectations and memories are more than mere images founded on previous experience.
Curiosity begins as an act of tearing to pieces or analysis.
The perceptive act is a reaction of the mind upon the object of which it is the perception.
We cannot therefore say that mental acts contain a cognitive as well as a conative element.
Hence, in desiring, the more the enjoyment is delayed, the more fancy begins to weave about the object images of future fruition, and to clothe the desired object with properties calculated to inflame the impulse.
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.
You can mark in desire the rising of the tide, as the appetite more and more invades the personality, appealing, as it does, not merely to the sensory side of the self, but to its ideal components as well.
But unfortunately Locke treated ideas of reflection as if they were another class of objects of contemplation beside ideas of sensation.
Mental life is indeed practical through and through. It begins in practice and it ends in practice.
Psychology is the science of the act of experiencing, and deals with the whole system of such acts as they make up mental life.
The mental act of sensation which issues in reflex movement is so simple as to defy analysis.
The sensory acts are accordingly distinguished by their objects.
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.
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.
It is convenient to distinguish the two kinds of experience which have thus been described, the experienc-ing and the experienc-ed, by technical words.
The interval between a cold expectation and a warm desire may be filled by expectations of varying degrees of warmth or by desires of varying degrees of coldness.