If you want to change your life, do it flamboyantly and start immediately.

Man lives by habits indeed, but what he lives for is thrill and excitements. ... From time immemorial war has been ... the supremely thrilling excitement.

History is a bath of blood.

The most peculiar social self which one is apt to have is in the mind of the person one is in love with.

Since you make evil or good by your own thoughts, it is your ruling of your thoughts which proves to be your principal concern.

(Five) thinkers since Galileo, each informing his successor of what discoveries his own lifetime had seen achieved, might have passed the torch of science into our hands as we sit here in this room. Indeed, for the matter of that, an audience much smaller than the present one, an audience of some 5 or 6 score people, if each person in it could speak for his own generation, would carry us away to the black unknown of the human species, to days without a document or monument to tell their tale.

To begin with, our knowledge grows in spots. The spots may be large or small, but the knowledge ever grows all over... What you first gain from them is probably a small amount of new information, a few new definitions, or distinctions, or points of view. But while these special ideas are being added, the rest of your knowledge stands still, and only gradually will you 'line up' your previous opinions with the novelties I am trying to instil, and modify to some slight degree their mass.