A man must always live by his work, and his wages must at least be sufficient to maintain him. They must even upon most occasions be somewhat more; otherwise it would be impossible for him to bring up a family, and the race of such workmen could not last beyond the first generation.

Have lots of experiments, but make sure they're strategically focused.

The man scarce lives who is not more credulous than he ought to be... The natural disposition is always to believe. It is acquired wisdom and experience only that teach incredulity, and they very seldom teach it enough.

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

Every individual is continually exerting himself to find out the most advantageous employment for whatever capital he can command. It is his own advantage, indeed, and not that of the society which he has in view. But the study of his own advantage naturally, or rather necessarily, leads him to prefer that employment which is most advantageous to society... He intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was not part of his intention

When the profits of trade happen to be greater than ordinary, over-trading becomes a general error both among great and small dealers.

The ancient Egyptians had a superstitious antipathy to the sea; a superstition nearly of the same kind prevails among the Indians; and the Chinese have never excelled in foreign commerce.