One of history's most influential thinkers was born on August 29th, 1632. Because of his contributions to government and constitutional theory, John Locke is widely regarded as the father of liberalism. Raised in the violence of the English Civil War, he tried to establish the basis for a constitutional government that would limit sovereign power.

He began with a 'state of nature' in which people had the right to self-preservation, to safeguard their life, health and property. Property rights are acquired when people 'mix their labour' with God's gifts, such as by catching fish or picking berries. The development of agriculture and money enabled people to accumulate surplus property, and made it possible for the surplus property of some people to be used by others. Initially acting as their own judge in disputes, people eventually form civil governments through a contract to protect their rights. This is a two-way contract in which government has the duty to protect those rights, and loses the consent of the governed if it violates them. If it does so, it becomes illegitimate, and its overthrow is justified. Locke's account thus differed dramatically from that of Thomas Hobbes, whose sovereign was not bound by the contract the people signed with each other.

Locke developed these themes in his "Two Treatises on Civil Government" (1690), and provided a justification for the Glorious Revolution of 1689, in which the autocratic King James II had been replaced by William III, Prince of Orange, and his wife, Mary, and constitutional government established.  Locke drew on his twin themes of natural rights and social contract, determined to refute any notion of a 'divine right of kings,' and to establish that government is not "merely the product of force and violence," but takes place with the consent of the governed. Locke had been developing these ideas during his self-imposed exile from England, and heavily influenced the 1689 Bill of Rights.

Locke had major influence on the American Revolutionaries, and his ideas can be seen permeating both the Declaration of Independence and the first ten amendments to the Constitution that make up the Bill of Rights. He has been described by some as the intellectual foundation of government by consent, and is thus a major theoretician behind the institution of democratic elections that can give that consent.

Such a contribution would alone have made Locke a remarkable thinker, but he influenced the modern world in another major way. In his "Essay Concerning Human Understanding" (1690), he sets out the empirical basis behind modern scientific method, rejecting the Cartesian notion of pre-existing concepts in favour of one in which the ideas come to us through our senses, the things we observe. We then process these ideas and they form the basis of our knowledge. Our knowledge is thus derived from our experience.

Locke thought that experience and experiment are fundamental. He wrote, "whatever I write, as soon as I discover it not to be true, my hand shall be the forwardest to throw it into the fire." Anything that can be shown by observation and experiment to be inaccurate must be rejected.

The fact that Locke made outstanding contributions in both the theory of government and the theory of knowledge makes him one of the Enlightenment's most influential thinkers and one of its brightest stars. He helped shape the world we live in today.