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

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.

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.

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.

For psychological purposes the most important differences in conation are those in virtue of which the object is revealed as sensed or perceived or imaged or remembered or thought.

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

The perceptive act is a reaction of the mind upon the object of which it is the perception.