Agriculture is the art of deriving from the earth the most valuable organic productions. He who exercises this art, seeks to obtain profit by causing to grow, and by using, its animal and vegetable productions. The more considerable the gain derived, therefore, the better is the object accomplished. The most perfect agriculture is, evidently, that which produces, by the application of labour, the largest and the most permanent profit in comparison with the means employed. Systematic agriculture ought, then, to teach us all the circumstances by means of which we may derive the most considerable profit by the practice of the art.

p. 1. - The Principles of Agriculture, 1844 - Section I: The fundamental principles