Niccolo Machiavelli (1469 - 1527)

Scientific developments took place from Copernicus through Kepler and then Galileo culminating to Newton imparted developments in other fields also. One of the most important development of these is political philosophy.Niccolo Machiavelli (1469 - 1527) , born four years before Copernicus was the most important .
He puts his ideas in his book " The Prince" published in 1513
Niccolò di Bernardo dei Machiavelli  was an Italian Renaissance historian, politician, diplomat, philosopher, humanist, and writer. He has often been called the founder of modern political science. He was for many years a senior official in the Florentine Republic, with responsibilities in diplomatic and military affairs. He also wrote comedies, carnival songs, and poetry. His personal correspondence is renowned in the Italian language. He was secretary to the SecondChancery of the Republic of Florence from 1498 to 1512, when the Medici were out of power. He wrote his most renowned work The Prince (Il Principe) in 1513. 
.Machiavelli was born in Florence, Italy, the third child and first son of attorney Bernardo di Niccolò Machiavelli and his wife, Bartolomea di Stefano Nelli. The Machiavelli family is believed to be descended from the old marquesses of Tuscany and to have produced thirteen Florentine Gonfalonieres of Justice,^[ one of the offices of a group of nine citizens selected by drawing lots every two months and who formed the government, or Signoria; but he was never a full citizen of Florence because of the nature of Florentine citizenship in that time even under the republican regime. Machiavelli married Marietta Corsini in 1502.
Machiavelli's best-known book Il Principe contains several maxims concerning politics. Instead of the more traditional target audience of a hereditary prince, it concentrates on the possibility of a "new prince". To retain power, the hereditary prince must carefully balance the interests of a variety of institutions to which the people are accustomed. By contrast a new prince has the more difficult task in ruling: He must first stabilize his newfound power in order to build an enduring political structure. Machiavelli suggests that the social benefits of stability and security can be achieved in the face of moral corruption. Machiavelli believed that public and private morality had to be understood as two different things in order to rule well. As a result, a ruler must be concerned not only with reputation, but also must be positively willing to act immorally at the right times. As a political theorist, Machiavelli emphasized the occasional need for the methodical exercise of brute force or deceit including extermination of entire noble families to head off any chance of a challenge to the prince's authority..