Human experience, which is constantly contradicting theory, is the great test of truth. A system, built upon the discoveries of a great many minds, is always of more strength, than what is produced by the mere workings of any one mind, which, of itself, can do very little. There is not so poor a book in the world that would not be a prodigious effort were it wrought out entirely by a single mind, without the aid of prior investigators.

Language is only the instrument of science, and words are but the signs of ideas.

He that writes may be considered as a kind of general challenger, whom every one has a right to attack; since he quits the common rank of life, steps forward beyond the lists, and offers his merit to the public judgement. To commence author is to claim praise, and no man can justly aspire to honour, but at the hazard of disgrace.

But the distant hope of being one day useful or eminent ought not to mislead us too far from that study which is equally requisite to the great and mean, to the celebrated and obscure; the art of moderating the desires, of repressing the appetites; and of conciliating or retaining the favour of mankind.

The most fatal disease of friendship is gradual decay, or dislike hourly increased by causes too slender for complaint, and too numerous for removal.

Courage is a quality so necessary for maintaining virtue, that it is always respected, even when it is associated with vice.

It is very natural for young men to be vehement, acrimonious and severe. For as they seldom comprehend at once all the consequences of a position, or perceive the difficulties by which cooler and more experienced reasoners are restrained from confidence, they form their conclusions with great precipitance. Seeing nothing that can darken or embarrass the question, they expect to find their own opinion universally prevalent, and are inclined to impute uncertainty and hesitation to want of honesty, rather than of knowledge.