That is simply to say, there is active or passive observation--the things which we seek or which come to us unsought.
And the "seeking for," or spontaneous action can be materially aided and made persevering, if before we begin the search or set about devoting Attention to anything, we pause, as it were, to determine or resolve that we _will_ be thorough, and not leave off until we shall have mastered it.

For strange as it may seem, the doing this actually has in most cases a positive, and very often a remarkable result, as the reader may very easily verify for himself.

This Forethought is far more easily awakened, or exerted, than Attention itself, but it prepares it, just as Attention prepares Interest.
Attention is closely allied to Memory; when we would give attention to a subject for continued consideration, we must "memorize" it, or it will vanish.

Involuntary memory excited by different causes often compels us to attend to many subjects whether we will or not.

Everyone has been haunted with images or ideas even unto being tormented by them; there are many instances in which the Imagination has given them objective form, and they have appeared visibly to the patient.