It is not to be forgotten that what we call rational grounds for our beliefs are often extremely irrational attempts to justify our instincts.

Veracity is the heart of morality.

A well-worn adage advises those who set out upon a great enterprise to count the cost, yet some of the greatest enterprises have succeeded because the people who undertook them did not count the cost.

Thoughtfulness for others, generosity, modesty, and self-respect are the qualities which make a real gentleman or lady.

Give unqualified assent to no propositions but those the truth of which is so clear and distinct that they cannot be doubted. The enunciation of this first great commandment of science consecrated doubt.

The birth of science was the death of superstition.

Living things have no inertia, and tend to no equilibrium.