The Wealth of Nations by Part 1 Chapter 10 Page 2

Every man’s interest would prompt him to seek the advantageous, and to shun the disadvantageous employment.

Pecuniary wages and profit, indeed, are everywhere in Europe extremely different according to the different employments of labour and stock. But this difference arises partly from certain circumstances in the employments themselves, which, either really, or at least in the imaginations of men, make up for a small pecuniary gain in some, and counterbalance a great one in others; and partly from the policy of Europe, which nowhere leaves things at perfect liberty.

The particular consideration of those circumstances and of that policy will divide this chapter into two parts.

Part 1: Inequalities arising from the Nature of the Employments themselves