Thou ought to be nice, even to superstition, in keeping thy promises, and therefore equally cautious in making them.

The true law of the race is progress and development. Whatever civilization pauses in the march of conquest, it is overthrown by the barbarian.

By a peculiar prerogative, not only each individual is making daily advances in the sciences, and may makes advances in morality, but all mankind together are making a continual progress in proportion as the universe grows older; so that the whole human race, during the course of so many ages, may be considered as one man, who never ceases to live and learn.

It is curious to note the old sea-margins of human thought. Each subsiding century reveals some new mystery; we build where monsters used to hide themselves.

The world owes all its onward impulses to men ill at ease. The happy man inevitably confines himself within ancient limits.

All our progress is an unfolding, like a vegetable bud. You have first an instinct, then an opinion, then a knowledge as the plant has root, bud, and fruit. Trust the instinct to the end, though you can render no reason.

Furious activity is no substitute for understanding.

We ought not be over anxious to encourage innovation, in case of doubtful improvement, for an old system must ever have two advantages over a new one; it is established and it is understood.

All progress is based on a universal innate desire on the part of every organism to live beyond its income.

The grandest of all laws is the law of progressive development. Under it, in the wide sweep of things, men grow wiser as they grow older, and societies better.