New opinions often appear first as jokes and fancies, then as blasphemies and treason, then as questions open to discussion, and finally as established truths.

We must always think about things, and we must think about things as they are, not as they are said to be.

All great truths begin as blasphemies.

Science is always simple and profound. It is only half truths that are dangerous.

If you leave the smallest corner of your head vacant for a moment, other people's opinions will rush in from all quarters

Dying is a troublesome business: there is pain to be suffered, and it wrings one's heart; but death is a splendid thing—a warfare accomplished, a beginning all over again, a triumph. You can always see that in their faces.