Confide not in the firmness of your principles, or the steadfastness of your integrity. Be always vigilant and fearful. Never think you have enough of knowledge, and let not your caution slumber for a moment, for you know not when danger is near.

All men are, at times, influenced by inexplicable sentiments. Ideas haunt them in spite of all their efforts to discard them. Prepossessions are entertained, for which their reason is unable to discover any adequate cause. The strength of a belief, when it is destitute of any rational foundation, seems, of itself, to furnish a new ground for credulity. We first admit a powerful persuasion, and then, from reflecting on the insufficiency of the ground on which it is built, instead of being prompted to dismiss it, we become more forcibly attached to it.

Confide not in the firmness of your principles, or the steadfastness of your integrity. Be always vigilant and fearful. Never think you have enough of knowledge, and let not your caution slumber for a moment, for you know not when danger is near.

Ideas exist in our minds that can be accounted for by no established laws.

I used to suppose that certain evils could never befall a being in possession of a sound mind; that true virtue supplies us with energy which vice can never resist; that it was always in our power to obstruct, by his own death, the designs of an enemy who aimed at less than our lives.

How slender is the accommodation which nature has provided for man.

I said to myself, we must die. Sooner or later, we must disappear forever from the face of the earth. Whatever be the links that hold us to life, they must be broken. This scene of existence is, in all its parts, calamitous.