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.

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

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.

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.

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.