[T]here is very little difference between one person and another, but what little difference ther eis, is very important.

An educated memory depends on an organized system of associations; and its goodness depends on two of their peculiarities: first, on the persistency of the associations; and, second, on their number.

The ultimate test of what a truth means is the conduct it dictates or inspires.

Our life is always deeper than we know, is always more divine than it seems, and hence we are able to survive degradations and despairs which otherwise must engulf us.

Our theories are wedged and controlled as nothing else is. Yet sometimes alternative theoretic formulas are equally compatible with all the truths we know, and then we choose between them for subjective reasons. We choose the kind of theory to which we are already partial: we follow 'elegenace' or 'economy'

A little cooling down of animal excitability and instinct, a little loss of animal toughness, a little irritable weakness and descent of the pain-threshold, will bring the worm at the core of all our usual springs of delight into full view, and turn us into melancholy metaphysicians.

Every way of classifying a thing is but a way of handling it for some particular purpose.