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.

The mental act of sensation which issues in reflex movement is so simple as to defy analysis.

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

It is more difficult to designate this form of conation on its practical side by a satisfactory name.

Curiosity begins as an act of tearing to pieces or analysis.

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.

When we come to images or memories or thoughts, speculation, while always closely related to practice, is more explicit, and it is in fact not immediately obvious that such processes can be described in any sense as practical.