In all determinations of morality, this circumstance of public utility is ever principally in view; and wherever disputes arise, either in philosophy or common life, concerning the bounds of duty, the questions cannot, by any means, be decided with greater certainty, than by ascertaining, on any side, the true interests of mankind. If any false opinion, embraced from appearances, has been found to prevail; as soon as farther experience and sounder reasoning have given us juster notions of human affairs, we retract our first sentiment, and adjust anew the boundaries of moral good and evil.

If we confine ourselves to a general and distant reflection on the ills of human life, that can have no effect to prepare us for them. If by close and intense meditation we render them present and intimate to us, that is the true secret for poisoning all our pleasures, and rendering us perpetually miserable.

Custom is the great guide to human life.

Municipal laws are a supply to the wisdom of each individual; and, at the same time, by restraining the natural liberty of men, make private interest submit to the interest of the public.

It seems certain, that though a man, in a flush of humour, after intense reflection on the many contradictions and imperfections of human reason, may entirely renounce all belief and opinion, it is impossible for him to persevere in this total scepticism, or make it appear in his conduct for a few hours.

Reason, in a strict sense, as meaning the judgment of truth and falsehood, can never, of itself, be any motive to the will, and can have no influence but so far as it touches some passion or affection. Abstract relations of ideas are the object of curiosity, not of volition. And matters of fact, where they are neither good nor evil, where they neither excite desire nor aversion, are totally indifferent, and whether known or unknown, whether mistaken or rightly apprehended, cannot be regarded as any motive to action.

Interest is the barometer of the state.