Even those to whom Providence has allotted greater strength of understanding can expect only to improve a single science.

Ignorance cannot always be inferred from inaccuracy; knowledge is not always present.

What is easy is seldom excellent.

Our minds, like our bodies, are in continual flux; something is hourly lost, and something acquired.... Do not suffer life to stagnate; it will grow muddy for want of motion: commit yourself again to the current of the world.

Pity is not natural to man. Children are always cruel. Savages are always cruel. Pity is acquired and improved by the cultivation of reason. We may have uneasy sensations from seeing a creature in distress, without pity; for we have not pity unless we wish to relieve them.

Truth has no gradations; nothing which admits of increase can be so much what it is, as truth is truth. There may be a strange thing, and a thing more strange. But if a proposition be true, there can be none more true.

The vicious count their years; virtuous, their acts.