The great source of both the misery and disorders of human life, seems to arise from over-rating the difference between one permanent situation and another. Avarice over-rates the difference between poverty and riches: ambition, that between a private and a public station: vain-glory, that between obscurity and extensive reputation. The person under the influence of any of those extravagant passions, is not only miserable in his actual situation, but is often disposed to disturb the peace of society, in order to arrive at that which he so foolishly admires. The slightest observation, however, might satisfy him, that, in all the ordinary situations of human life, a well-disposed mind may be equally calm, equally cheerful, and equally contented. Some of those situations may, no doubt, deserve to be preferred to others: but none of them can deserve to be pursued with that passionate ardour which drives us to violate the rules either of prudence or of justice; or to corrupt the future tranquillity of our minds, either by shame from the remembrance of our own folly, or by remorse from the horror of our own injustice.

The prudent man always studies seriously and earnestly to understand whatever he professes to understand, and not merely to persuade other people that he understands it; and though his talents may not always be very brilliant, they are always perfectly genuine. He neither endeavours to impose upon you by the cunning devices of an artful impostor, nor by the arrogant airs of an assuming pedant, nor by the confident assertions of a superficial and imprudent pretender. He is not ostentatious even of the abilities which he really possesses. His conversation is simple and modest, and he is averse to all the quackish arts by which other people so frequently thrust themselves into public notice and reputation.

The subjects of every state ought to contribute towards the support of the government, as nearly as possible, in proportion to their respective abilities.

To attempt to increase the wealth of any country, either by introducing or by detaining in it an unnecessary quantity of gold and silver, is as absurd as it would be to attempt to increase the good cheer of private families by obliging them to keep an unnecessary number of kitchen utensils.

No paint or dye can give so splendid a colour as gilding. The merit of their beauty is greatly enhanced by their scarcity. With the greater part of rich people, the chief enjoyment of riches consists in the parade of riches, which in their eye is never so complete as when they appear to possess those decisive marks of opulence which nobody can possess but themselves. In their eyes the merit of an object which is in any degree either useful or beautiful is greatly enhanced by its scarcity, or by the great labour which it requires to collect any considerable quantity of it, a labour which nobody can afford to pay but themselves.Book I, Chapter 11 - Rent of Land, part II

The interest of [businessmen] is always in some respects different from, and even opposite to, that of the public ... The proposal of any new law or regulation of commerce which comes from this order ... ought never to be adopted, till after having been long and carefully examined ... with the most suspicious attention. It comes from an order of men ... who have generally an interest to deceive and even oppress the public