Niccolo Machiavelli

Florentine diplomat, historian, and political philosopher — author of The Prince (1532) — whose ruthlessly realistic account of political power (it is better to be feared than loved; the ends justify the means) created modern political science.

Separates political analysis from moral prescription — Machiavelli's central move (describing how rulers actually behave rather than how they should behave) created the field of political realism and ended the medieval tradition of treating politics as applied ethics.