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

Both expectations and memories are more than mere images founded on previous experience.

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.

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

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

The sensory acts are accordingly distinguished by their objects.

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.