If nature has been frugal in her gifts and endowments, there is the more need of art to supply her defects. If she has been generous and liberal, know that she still expects industry and application on our part, and revenges herself in proportion to our negligent ingratitude. The richest genius, like the most fertile soil, when uncultivated, shoots up into the rankest weeds; and instead of vines and olives for the pleasure and use of man, produces, to its slothful owner, the most abundant crop of poisons.

Part I, Essay 16: The Stoic - Essays, Moral, Political, and Literary (1741-2; 1748)