Quotes from Alfred Marshall

Material goods consist of useful material things, and of all rights to hold, or use, or derive benefits from material things, or to receive them at a future time.

Slavery was regarded by Aristotle as an ordinance of nature, and so probably was it by the slaves themselves in olden time.

All labour is directed towards producing some effect.

Civilized countries generally adopt gold or silver or both as money.

And very often the influence exerted on a person's character by the amount of his income is hardly less, if it is less, than that exerted by the way in which it is earned.

All wealth consists of desirable things; that is, things which satisfy human wants directly or indirectly: but not all desirable things are reckoned as wealth.

It is common to distinguish necessaries, comforts, and luxuries; the first class including all things required to meet wants which must be satisfied, while the latter consist of things that meet wants of a less urgent character.

Every short statement about economics is misleading (with the possible exception of my present one).