The public is a bad guesser.

The mere understanding, however useful and indispensable, is the meanest faculty in the human mind and the most to be distrusted.

Thou hast the keys of Paradise, oh, just, subtle, and mighty opium!

There is a necessity for a regulating discipline of exercise that, whilst evoking the human energies, will not suffer them to be wasted.

There is first the literature of knowledge, and secondly, the literature of power. The function of the first is--to teach; the function of the second is--to move, the first is a rudder, the second an oar or a sail. The first speaks to the mere discursive understanding; the second speaks ultimately, it may happen, to the higher understanding or reason, but always through affections of pleasure and sympathy.

The burden of the incommunicable.

Nobody will laugh long who deals much with opium: its pleasures even are of a grave and solemn complexion.