It is false to suggest that men must turn away from his desires in the interest of a higher duty. Men only responds to duty if he desires to do so. To understand men, you must understand their desires and the relative strength of those desires.

In the part of this universe that we know there is great injustice, and often the good suffer, and often the wicked prosper, and one hardly knows which of those is the more annoying.

An extra-terrestrial philosopher, who had watched a single youth up to the age of twenty-one and had never come across any other human being, might conclude that it is the nature of human beings to grow continually taller and wiser in an indefinite progress towards perfection; and this generalization would be just as well founded as the generalization which evolutionists base upon the previous history of this planet.

The reason is, and by rights ought to be, slave to the emotions.

There is much pleasure to be gained from useless knowledge.

Public opinion is always more tyrannical towards those who obviously fear it than towards those who feel indifferent to it.

If an opinion contrary to your own makes you angry, that is a sign that you are subsciously aware of having no good reason for thinking as you do. [...] The most savage controversies are those about matters as to which there is no good evidence either way. Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion. So whenever you find yourself getting angry about a difference of opinion, be on your guard; you will probably find, on examination, that your belief is going beyond what the evidence warrants.