Philosopher. Locke is both a founder of the European tradition of philosophical empiricism, which puts primary emphasis on knowledge gained by our senses as revealed through our brain, and also a founder of the modern movement in favor of personal liberty, democracy, and the rights of the governed. Locke taught that every person had a right to life, liberty, and property. In his view, those were interrelated because if the state threatened property rights, citizens would be powerless to stand up for their rights to life and liberty. Jefferson famously modified Locke in the Declaration of Independence by speaking of "life, liberty, and the pursuit of happiness."