Our toil must be in silence, and our efforts all in secret; for this enlightened age, when men believe not even what they see, the doubting of wise men would be his greatest strength.

I counsel you, put down in record even your doubts and surmises. Hereafter it may be of interest to you to see how true you guess. We learn from failure, not from success.

There are mysteries which men can only guess at, which age by age they may solve only in part.

I am all in a sea of wonders. I doubt; I fear; I think strange things, which I dare not confess to my own soul.

We learn from failure, not from success!

Shy and proud men are more liable than any others to fall into the hands of parasites and creatures of low character. For in the intimacies which are formed by shy men, they do not choose, but are chosen.