Epicurus (341-270 BC) was, with Plato and Aristotle, one of the three great philosophers of the ancient world. He developed an integrated system of ethics and natural philosophy that, he claimed and many accepted, showed everyone the way to a life of the greatest happiness. The school that he founded remained open for 798 years after his death. While it lost place during the last 200 of these years, his philosophy held until then a wide and often decisive hold on the ancient mind.
The revival of Epicureanism in the 17th century coincided with the growth of scientific rationalism and classical liberalism. There can be no doubt these facts are connected. It may, indeed, be argued that the first was a leading cause of the second two, and that we are now living in a world shaped, in every worthwhile sense, by the ideas of Epicurus.