Of the few innocent pleasures left to men past middle life, the jamming of common sense down the throats of fools is perhaps the keenest.

A man has no reason to be ashamed of having an ape for his grandfather. If there were an ancestor whom I should feel shame in recalling it would rather be a man who plunges into scientific questions with which he has no real acquaintance, only to obscure them by an aimless rhetoric.

Education is the instruction of the intellect in the laws of Nature, under which name I include not merely things and their forces, but people and their ways; and the fashioning of the affections and of the will into an earnest and loving desire to move in harmony with those laws.

[Scientists] have learned to respect nothing but evidence, and to believe that their highest duty lies in submitting to it however it may jar against their inclinations.

As if to demonstrate, by a striking example, the impossibility of erecting any cerebral barrier between man and the apes, Nature has provided us, in the latter animals, with an almost complete series of gradations from brains little higher than that of a Rodent, to brains little lower than that of Man.

Agnosticism simply means that a man shall not say that he knows or believes that for which he has no grounds for professing to believe.

Protoplasm, simple or nucleated, is the formal basis of all life. It is the clay of the potter: which, bake it and paint it as hewill, remains clay, separated by artifice, and not by nature from the commonest brick or sun-dried clod.