The real price of everything, what everything really costs to the man who wants to acquire it, is the toil and trouble of acquiring it.

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

Every man lives by exchanging.

When we have read a book or poem so often that we can no longer find any amusement in reading it by ourselves, we can still take pleasure in reading it to a companion. To him it has all the graces of novelty.

The statesman who should attempt to direct private people in what manner they ought to employ their capitals would not only load himself with most unnecessary attention but assume an authority which could safely be trusted to no council and senate whatever, and which would nowhere be so dangerous as in the hands of man who have folly and presumption enough to fancy himself fit to exercise it.

Science is the great antidote to the poison of enthusiasm and superstition.

It is the natural effect of improvement, however, to diminish gradually the real price of almost all manufactures.