In existographies, Niccolo Machiavelli (1469-1527) (IQ:105|#180) (Cattell 1000:83) [RGM:54|1,500+] (Gottlieb 1000:40) (GPhE:#) (CR:53) was an Italian realism philosopher, historian, politician, and diplomat, best known for his 1513 leadership advice book The Prince, political ethics discourse advocating an ‘ends outweigh the means’ (or "end justifies the means") philosophy; influential to: Francis Bacon and Vilfredo Pareto.
Machiavelli, according to Russian-born American sociologist Pitirim Sorokin, was the first advance the idea of the cyclic development of societies. 
Italian engineer turned socioeconomist Vilfredo Pareto, supposedly, was inspired by Machiavelli’s distinction between two types of human instincts, one oriented toward tradition (lions) and one toward innovation (foxes), and that this, in part, is from where he gets is circulation of elites theory.
Quotes | On
The following are noted quotes and or tributes:
“We are much beholden to Machiavelli and others, that write what men do, and not what they ought to do. For it is not possible to join serpentine wisdom with the columbine innocency, except men know exactly all the conditions of the serpent; his baseness and going upon his belly, his volubility and lubricity, his envy and sting, and the rest; that is, all forms and natures of evil. For without this, virtue lieth open and unfenced. Nay, an honest man can do no good upon those that are wicked, to reclaim them, without the help of the knowledge of evil.”
— Francis Bacon (1605), The Advancement of Learning (Ѻ) 
“Machiavelli’s chief contribution to political thought lies in his freeing political action from moral considerations.”
— Daniel Donno (1981), “Introduction” to The Prince 
Quotes | By
The following are noted quotes:
“It must be considered that there is nothing more difficult to carry out nor more doubtful of success, nor more dangerous to handle, than to initiate a new order of things. For the reformer has enemies in all those who profit by the new order, and only lukewarm defenders in all those who would profit by the new order, this lukewarmness arising partly for fear of their adversaries, who have the laws in their favor; and partly from the incredulity of men, who do not truly believe in anything new until they have had actual experience of it.”
— Niccolo Machiavelli (1513), The Prince (§6)
“The way men live is so far removed from the way they ought to live that anyone who abandons what is for what should be pursues his downfall.”
— Niccolo Machiavelli (1532), The Prince 
“Christian principles seem to me to have made men feeble, and caused them to become an easy prey to evil-minded men, who can control them more securely, seeing that he great body of men, for the sake of gaining paradise, are more disposed to endure injuries than to avenge them.”
— Niccolo Machiavelli (1513), The Prince; cited by Jennifer Hecht (2004) in Doubt: a History (pg. 273)
1. (a) Bacon, Francis. (1605). The Advancement of Learning (bk. II, xxi, 9). Publisher.
(b) Henderson, Lawrence J. (1935). Pareto’s General Sociology: a Physiologists Interpretation (pg. 3). Harvard University Press.
(c) Note: the above “not what they ought to do” seems to be reference to his 1517 Discourses. (Ѻ)
2. Raikhlin, Raddai. (2010). Military Sociology: Collapse of the Israel Defense Forces (translator: Tanya Chepkova) (abs). CreateSpace.
3. (a) Machiavelli, Niccolo. (1513). The Prince (pg. 56). Bantam, 1981.
(b) Rigney, Daniel. (2001). The Metaphorical Society: an Invitation to Social Theory (pg. 46). Rowman & Littlefield.
4. (a) Donno, Daniel. (1981). “Introduction”, in The Prince (by Niccolo Machiavelli). Bantam Classic.
(b) Rigney, Daniel. (2001). The Metaphorical Society: an Invitation to Social Theory (pg. 67). Rowman & Littlefield.
● Niccolo Machiavelli – Wikipedia.