Every opinion which embodies somewhat of the portion of truth which the common opinion omits, ought to be considered precious, with whatever amount of error and confusion that truth may be blended.

If opponents of all important truths do not exist, it is indispensable to imagine them and supply them with the strongest arguments which the most skillful devil's advocate can conjure up.

Seeming contentment is real discontent, combined with indolence or self-indulgence, which, while taking no legitimate means of raising itself, delights in bringing others down to its own level.

Ask yourself whether you are happy and you cease to be so. The only chance is to treat not happiness, but some end external to it, as the purpose of life.

Human existence is girt round with mystery: the narrow region of our experience is a small island in the midst of a boundless sea. To add to the mystery, the domain of our earthly existence is not only an island of infinite space, but also in infinite time. The past and the future are alike shrouded from us: we neither know the origin of anything which is, nor its final destination.

All action is for the sake of some end; and rules of action, it seems natural to suppose, must take their whole character and color from the end to which they are subservient.

The despotism of custom is everywhere the standing hindrance to human advancement.