It may indeed be doubted, whether butcher's meat is any where a necessary of life. Grain and other vegetables, with the help of milk, cheese, and butter, or oil, where butter is not to be had, it is known from experience, can, without any butcher's meat, afford the most plentiful, the most wholesome, the most nourishing, and the most invigorating diet.

Chapter II, Part II, Appendix to Articles I and II. - The Wealth of Nations (1776) - Book V