understanding with ideas, is the perception of the operations of our
own mind within us, as it is employed about the ideas it has got;
which operations, when the soul comes to reflect on, and consider, do
furnish the understanding with another set of ideas, which could not
be had from things without; and such are Perception, Thinking,
Doubting, Believing, Reasoning, Knowing, Willing, and all the
different actings of our own minds; which we being conscious of, and
observing in ourselves, do, from these, receive into our
understandings as distinct ideas, as we do from bodies affecting our
senses. This source of ideas every man has wholly in himself; and
though it be not sense as having nothing to do with external objects,
yet it is very like it, and might properly enough be called internal
sense. But, as I call the other sensation, so I call this
_reflection_; the ideas it affords being such only as the mind gets,
by reflecting on its own operations within itself."[3]

[3] Locke, _Essay_, ii, 1, Secs. 2-4.

Here Locke is thinking of the distinction between two attitudes of
mind, which, however difficult it may be to state satisfactorily, must
in some sense be recognized. The mind, undoubtedly, in virtue of its
powers of perceiving and thinking--or whatever they may be--becomes
through a temporal process aware of a spatial world in its varied
detail. In the first instance, its attention is absorbed in the world
of which it thus becomes aware; subsequently, however, it is in some
way able to direct its attention away from this world to the
activities in virtue of which it has become aware of this world, and
in some sense to make itself its own object. From being conscious it
becomes self-conscious. This process by which the mind turns its
attention back upon itself is said to be a process of 'reflection'.
While we should say that it is by perception that we become aware of
things in the physical world, we should say that it is by reflection
that we become aware of our activities of perceiving, thinking,
willing, &c. Whatever difficulties the thought of self-consciousness
may involve, and however inseparable, and perhaps even temporally
inseparable, the attitudes of consciousness and self-consciousness may
turn out to be, the distinction between these attitudes must be
recognized. The object of the former is the world, and the object of
the latter is in some sense the mind itself; and the attitudes may be
described a