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

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.

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

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

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

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