“He that doth not as other men do, but endeavoureth that which ought to be done, shall thereby rather incur peril than preservation; for whoso laboureth to be sincerely perfect and good shall necessarily perish, living among men that are generally evil.”

Source: The Prince (1513), Ch. 15
Context: Many have imagined republics and principalities which have never been seen or known to exist in reality; for how we live is so far removed from how we ought to live, that he who abandons what is done for what ought to be done, will rather bring about his own ruin than his preservation.

Abt Vogler, ix.
Bartlett's Familiar Quotations, 10th ed. (1919)

The Notebooks of Leonardo Da Vinci (1938), XLV Prophecies

Source: A Heap o' Livin' (1916), Opportunity, p. 40.

Section I, p. 5–6
Natural Law; or The Science of Justice (1882), Chapter I. The Science of Justice.

Section 2, member 3, subsection 12.
The Anatomy of Melancholy (1621), Part I

Adam Bede (1859)

Original: (it) Molti si sono immaginate Repubbliche e Principati, che non si sono mai visti nè cognosciuti essere in vero; perchè egli è tanto discosto da come si vive, a come si doveria vivere, che colui che lascia quello che si fa per quello che si doveria fare, impara piuttosto la rovina, che la preservazione sua.
Source: The Prince (1513), Ch. 15; translated by W. K. Marriot

Nītiśataka 74; translated by B. Hale Wortham
Śatakatraya