Men can intoxicate themselves with ideas as effectually as with alcohol or with bang and produce, be dint of serious thinking, mental conditions hardly distinguishable from monomania.

As a natural process, of the same character as the development of a tree from its seed, or of a fowl from its egg, evolution excludes creation and all other kinds of supernatural intervention.

Life is too short to occupy oneself with the slaying of the slain more than once.

It ought not to be unpleasant to say that which one honestly believes or disbelieves. That it so constantly is painful to do so, is quite enough obstacle to the progress of mankind in that most valuable of all qualities, honesty of word or of deed.

The sceptics end in the infidelity which asserts the problem to be insoluble, or in the atheism which denies the existence of any orderly progress and governance of things: the men of genius propound solutions which grow into systems of Theology or of Philosophy, or veiled in musical language which suggests more than it asserts, take the shape of the Poetry of an epoch.

I wish you would let an old man, who has had his share of fighting, remind you that battles, like hypotheses, are not to be multiplied beyond necessity.

I do not say think as I think, but think in my way. Fear no shadows, least of all in that great spectre of personal unhappiness which binds half the world to orthodoxy.