A maxim is a conclusion upon observation of matters of fact, and is merely speculative; a "principle" carries knowledge within itself, and is prospective.

Greatness and goodness are not means, but ends! Hath he not always treasures, always friends, The good great man? Three treasures, love and light, And calm thoughts, regular as infants' breath; And three firm friends, more sure than day and night, Himself, his Maker, and the angel Death.

Poetry, even that of the loftiest, and seemingly, that of the wildest odes, [has] a logic of its own as severe as that of science; and more difficult, because more subtle, more complex, and dependent on more and more fugitive causes. In the truly great poets... there is a reason assignable, not only for every word, but for the position of every word.

The principle of the Gothic architecture is infinity made imaginable.

Some men are like musical glasses; to produce their finest tones you must keep them wet.

My eyes make pictures when they are shut.

A great mind must be androgynous.