THERE ARE TWO THINGS that don't have to mean anything, one is music and the other is laughter.

Two things fill the mind with ever new and increasing admiration and awe, the oftener and more steadily we reflect on them: the starry heavens above and the moral law within.

Act so as to use humanity, yourself and others, always as an end and never as a means to an end.

How then is perfection to be sought? Wherein lies our hope? In education, and in nothing else.

Reason can never prove the existence of God.

Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck.

Reason in a creature is a faculty of widening the rules and purposes of the use of all its powers far beyond natural instinct; it acknowledges no limits to its projects. Reason itself does not work instinctively, but requires trial, practice, and instruction in order gradually to progress from one level of insight to another.