Results should not be too voluntarily aimed at or too busily thought of. They are sure to float up of their own accord from a long enough daily work at a given matter.

It is only in the lonely emergencies of life that our creed is tested: then routine maxims fail, and we fall back on our gods.

In order to disprove the assertion that all crows are black, one white crow is sufficient.

The strenuous life tastes better

Many persons nowadays seem to think that any conclusion must be very scientific if the arguments in favor of it are derived from twitching of frogs' legs (especially if the frogs are decapitated) and that, on the other hand, any doctrine chiefly vouched for by the feelings of human beings (with heads on their shoulders) must be benighted and superstitious.

True ideas are those that we can assimilate, validate, corroborate, and verify. False ideas are those that we cannot

Truth, as any dictionary will tell you, is a property of certain of our ideas. It means their agreement, as falsity means their disagreement, with reality.