English thinker (Wrington, Somerset, 1632 - Oaks, Essex, 1704). This multifaceted man studied at the University of Oxford, where earned a doctorate in 1658. Although his specialty was medicine and maintained relations with renowned scientists of the time (such as Isaac Newton), John Locke was also a diplomat, theologian, Economist, Professor of ancient Greek and rhetoric, and achieved renown for his philosophical writings, which laid the foundations of liberal political thought.
Locke was approached with such ideas as a physician and Secretary was of the Earl of Shaftesbury, leader of the Whig, adversary of the absolutism of the monarchy in the England of Charles II and Jacobo II. Converted to the defence of parliamentary power, the own Locke was pursued and had to take refuge in Holland, where he returned after the triumph of the "glorious revolution" English of 1688.
Locke was one of the great ideologists of English Protestant elites that, clustered around the whigs, arrived to check the status by virtue of the revolution; and, as a result, his thinking has exercised a decisive influence on the political Constitution of the United Kingdom until today. He defended religious tolerance towards all the Protestant sects and even non-Christian religions; but the interested and partial nature of his liberalism was highlighted by excluding the right to tolerance both atheists and Catholics (the confrontation of the latter with the Protestants being the key of the religious conflicts that were bleeding to the British Isles and Europe as a whole).
In his most significant work, two essays on civil government (1690), sat the basic principles of liberal constitutionalism, postulating that every man is born with natural rights which the State aims to protect: fundamentally, the life, liberty and property. Based on the thinking of Hobbes, Locke supported the idea that the State is born from a 'social contract' originally, rejecting the traditional doctrine of the divine origin of power; but, unlike Hobbes, he argued that the Pact did not lead to the absolute monarchy, but it was revoked and he could only lead to a limited Government.
The authority of the State was the will of the citizens, who would be disconnected from the duty of obedience when their rulers conculcaran these inalienable natural rights. The people would thus not only the right to modify the legislative discretion (idea from where comes the practice of periodic elections in liberal States), but also the overthrow rulers diminished by a tyrannical exercise of power (idea that Jefferson and the American revolutionaries supported for rebelling against Great Britain in 1776 as well as the French revolutionaries to rise up against the absolutism of Luis XVI in 1789).
Locke defended the separation of powers as a way of balancing them together and prevent any degenerated towards despotism; but, to the supremacy of a legislature representative of the majority, can be considered him also a theorist of democracy, towards which end up evolving liberal regimes. By legitimate it is, however, no power should exceed certain limits (hence the idea of putting them in writing in a Constitution).
This type of ideas inspired liberalism Anglo-Saxon (reflected promptly in the constitutions of Britain and United States) and, indirectly, also to the rest of the world (through French, such as Montesquieu and Voltaire illustrated). Less incidence had properly philosophical thought from Locke, based on a theory of knowledge empiricist inspired by Bacon and Descartes.