It is always advisable to perceive clearly our ignorance.

When it was first said that the sun stood still and world turned round, the common sense of mankind declared the doctrine false; but the old saying of Vox populi, vox Dei [the voice of the people is the voice of God], as every philosopher knows, cannot be trusted in science.

Describing laughter: The sound is produced by a deep inspiration followed by short, interrupted, spasmodic contractions of the chest, and especially the diaphragm... the mouth is open more or less widely, with the corners drawn much backwards, as well as a little upwards; and the upper lip is somewhat raised.

I have no great quickness of apprehension or wit which is so remarkable in some clever men, for instance Huxley

This fundamental subject of Natural Selection will be treated at some length in the fourth chapter; and we shall then see how Natural Selection almost inevitably causes much Extinction of the less improved forms of life and induces what I have called Divergence of Character.

Traveling ought also to teach him distrust; but at the same time he will discover, how many truly kind-hearted people there are, with whom he never before had, or ever again will have any further communication, who yet are ready to offer him the most disinterested assistance.

Looking to future generations, there is no cause to fear that the social instincts will grow weaker... the social instincts, - the prime principle of man's moral constitution - with the aid of active intellectual powers and the effects of habit, naturally lead to the golden rule, "As ye would that men should do to you; do ye to them likewise"; and this lies at the foundation of morality.