the only way in which a human being can make some approach to knowing the whole of a subject, is by hearing what can be said about it by persons of every variety of opinion, and studying all modes in which it can be looked at by every character of mind. No wise man ever acquired his wisdom in any mode but this; nor is it in the nature of human intellect to become wise in any other manner.

The habit of analysis has a tendency to wear away the feelings.

Almost all rich veins of original and striking speculation have been opened by systematic half-thinkers.

Everything must be free to be written and published without restraint.

Seeming contentment is real discontent, combined with indolence or self-indulgence, which, while taking no legitimate means of raising itself, delights in bringing others down to its own level.

The ends of scientific classification are best answered, when the objects are formed into groups respecting which a greater number of general propositions can be made, and those propositions more important, than could be made respecting any other groups into which the same things could be distributed. ... A classification thus formed is properly scientific or philosophical, and is commonly called a Natural, in contradistinction to a Technical or Artificial, classification or arrangement.

Christian morality (so called) has all the characters of a reaction.... In its horror of sensuality, it made an idol of asceticism, which has been gradually compromised away into one of legality. It holds out the hope of heaven and the threat of hell, as the appointed and appropriate motives to a virtuous life - in this falling far below the best of the ancients, and doing what lies in it to give to human morality an essentially selfish character.... It is essentially a doctrine of passive obedience; it inculcates submission to all authorities found established.