And, to conclude, he that leaveth nothing to Chance will do few things ill, but he will do very few things.

George Savile, Marquis of Halifax (1633–1695) English politician and essayist

“Of Caution and Suspicion,” Political, Moral, and Miscellaneous Thoughts and Reflections (1750)
    (Source)

Sometimes incorrectly attributed to Edward Wood, Earl of Halifax (1881-1959).