The one condition under which all powers, and consequently the intellectual faculties, are developed, is exercise. - Sir William Hamilton, 9th Baronet

On this ground I would rest one of the pre-eminent utilities of mental philosophy. That it comprehends all the sublimest objects of our theoretical and moral interest; that every (natural) conclusion concerning God, the soul, the present worth and the future destiny of man, is exclusively deduced from the philosophy of mind, will be at once admitted.

The intellect," says Aristotle... "is perfected, not by knowledge but by activity..." and... "The arts and sciences are powers, but every power exists only for the sake of action; the end of philosophy... is not knowledge, but the energy conversant about knowledge.

Analysis and synthesis, though commonly treated as two different methods, are, if properly understood, only the two necessary parts of the same method. Each is the relative and correlative of the other. Analysis, without a subsequent synthesis, is incomplete; it is a mean cut off from its end. Synthesis, without a previous analysis, is baseless; for synthesis receives from analysis the elements which it recomposes.