Epicureanism is named after the philosopher Epicurus, who founded a school of teaching in Athens that continued for seven centuries after his death. Epicurus (342–270 b.c.e.) was a citizen of Athens, raised on the island of Samos.

His contribution was aimed at the practical application of philosophy and its role in enabling people to lead a pleasurable and virtuous life. His ideas are completely distinct from the slanderous attacks made on him by later thinkers, who have given to Epicureanism a pejorative sense of gluttony and unbridled hedonism.

Writings of Epicurus that have survived, notably letters to Herodotus and Menoecus, contain only the restatement of the works of others, with one principal exception. This was in the area of atomism.

The basis of atomism is that the phenomena of the universe can be explained by the interactions of the smallest independently existing particles of matter (atoms) that follow observable physical laws in predictable ways.

In other words, there is no fundamental need for the gods to exist for the universe also to exist. Consequently, humanity should be freed from the terror inflicted upon it by anxiety of what new diseases and disasters the gods might next release and in concern that those disasters are the fault of people suffering from them.

To this belief Epicurus added the innovation that some atoms will voluntarily bend from the paths that would otherwise cause them to descend from the skies to the earth.

This voluntary movement, the cause for which was not properly explained, had the effect of preventing people from feeling that they were trapped in a mechanistic universe with no fundamental meaning or purpose.

Epicurus taught in a garden in Athens from approximately 306 b.c.e. until his death. Athens had also witnessed the brilliance of Aristotle within the preceding 20 years and the astonishing conquests of Alexander the Great in Asia Minor and Egypt.

Greek culture was becoming one of the most dynamic forces of the world. Yet, a time of such change and innovation also led to a sense of impermanence and the fear of the unknown.

According to Epicurus, the sensible approach of any adult was to seek the maximization of pleasure and peace, rather than appease or appeal to the supernatural. This is the philosophy of hedonism, which holds the seeking of pleasure to be the ultimate purpose of life.

This does not mean, however, that people should heedlessly chase after any immediate pleasurable sensation without consideration of the future or of any other person. The sensible person should recognize that different forms of pleasure inevitably bring pain.

For example, the thoughtless drinking of wine will lead to the pain of a hangover, while the lusts of a criminal nature will lead to the misery of prosecution. As a result, the properly hedonistic person is also a virtuous person who selects pleasures that do not cause pain to themselves or to others.

However, owing to his atomistic beliefs, Epicurus would have acknowledged that virtue is intrinsically of no value. This made his position rather paradoxical. His belief in the gods, whom he conceived of as living blissful existences while completely ignoring humanity, is also illogical.

If there is no necessity for the gods to exist, as well as no meaningful way to detect their presence, then why would Epicurus claim their existence? It is possible that, bearing in mind the practicality of his teaching, he simply wished to avoid the political danger of denying the existence of the gods.

The Epicurean school continued after the death of its founder and became particularly prominent in Rome. Two of the tutors of Cicero were Epicureans, and Seneca defended the beliefs of Epicurus against the attacks of the religious minded and particularly the Christians.

The conversion of the emperor Constantine the Great to Christianity in 313 c.e. signaled the end of Epicureanism as part of the mainstream of intellectual discourse.

One problem was that Epicureanism showed little ability to innovate or develop. Once it was accepted that Epicurus had identified the proper way to live, there was little to discuss, and people should just go about practicing what he taught.

As Lucretius wrote, he was "... the man in genius who o’er-topped / The human race, extinguishing all others, / As sun, in ether arisen, all the stars". The inability to adapt effectively condemned Epicureanism to continual condemnation by religious believers who characterized it as little more than egotistic selfishness.

Humanists who tried to support Epicureanism were condemned as libertines. The poem "De Rerum Natura" ("On the Nature of the Universe") by the Roman philosopher and Stoic Lucretius explains Epicureanism in its fullest form.