Epicurus, an illustrious Greek philosopher, was born 341 B.C., in the island of Samos, where his father, Neocles, was a schoolmaster. At the age of eighteen he repaired to Athens, but his stay was short, and he returned to Asia. He had attached himself to the study of philosophy, especially that of Democritus; his own scheme of physics is evidently based on the atomic system of Democritus. At Mitylene, in his thirty-second year, he first opened a school of philosophy; and there and at Lampsacus he taught for five years. In 307 B.C. he returned to Athens, and established a school of philosophy in a garden which he purchased and laid out for the purpose. From this circumstance his followers were called the 'philosophers of the garden.' Although Epicurus laid down the doctrine that pleasure is the chief good, the life that he and his friends led was one of the greatest temperance and simplicity. They were content, we are told, with a small cup of light wine, and all the rest of their drink was water; and an inscription over the gate promised to those who might wish to enter no better fare than barley-cakes and water. The calumnies which the Stoics circulated concerning him are undeserving of notice, and were at no time generally believed. Epicurus's success as a teacher was signal; great numbers flocked to his school from all parts of Greece and from Asia Minor, most of whom became warmly attached to their master, as well as to his doctrines, for Epicurus seems to have been characterised not less by amiability and benevolence than by force of intellect. He died 270 B.C., in the seventy-second year of his age.
Epicurus was a most voluminous writer. According to Diogenes Laertius, he left 300 volumes on Natural Philosophy, Atoms and the Vacuum, Love, the Chief Good, Justice, and many other subjects. These works are lost: the only writings of Epicurus that have come down to us are three letters, a few fragments from the Volumina Herculanensia, and a number of detached sentences or sayings, preserved by Diogenes Laertius. The principal sources of our knowledge of the doctrines of Epicurus are Cicero, Plutarch, and, above all, Lucretius, whose great poem, De Rerum Natura, contains substantially the Epicurean philosophy.
Although the majority of Epicurus's writings referred to natural philosophy, he seems to have studied nature with a moral rather than a scientific design. According to him, the great evil that afflicted men—the incubus on human happiness—was fear; fear of the gods and fear of death. To get rid of these two fears was the ultimate aim of all his speculations on nature.
He regarded the universe (to pan) as corporeal, and as infinite in extent and eternal in duration. He recognised two kinds of existence—that of bodies, and that of vacuum, 'the void'—i.e. space, or the intangible nature. Of his bodies, some are compounds, and some atoms or indivisible elements, out of which the compounds are formed. The world, as we now see it, is produced by the collision and whirling together of these atoms. He also held the doctrine of perception by images (Gr. eidōla), which are incessantly streaming off from the surface of all bodies, and which are necessary to bring us into rapport with the world without. In psychology he was a materialist, holding that the soul is a bodily substance, composed of subtle particles disseminated through the whole frame.
In seeking to understand the phenomena of the heavens he has no scientific end in view; his sole object is to enable the mind to account for them to itself, without the necessity of imagining any supernatural agency at work. He did not deny that there are gods; but he strenuously maintained that as 'happy and imperishable beings' they could have nothing to do with the affairs of the universe or of men. 'Beware,' he says, 'of attributing the revolutions of the heaven, and eclipses, and the rising and setting of stars, either to the original contrivance or continued regulation of such a being. For business, and cares, and anger, and benevolence are not accordant with happiness, but arise from weakness, and fear, and dependence on others.'
Having proved in his psychology that the dissolution of the body involves that of the soul, Epicurus argues that the most terrible of all evils, death, is nothing to us, 'since when we are, death is not; and when death is, we are not. It is nothing, then, to the dead or the living; for to the latter it is not near, and the former are no longer in existence.'
He held that pleasure was the chief good, and it is from a misapprehension of the meaning of this word as used by him that the term Epicurean came to signify one who indulged his sensual appetites without stint or measure. At the same time, it is easy to see that the use of the word 'pleasure' was calculated to produce the mischievous results with which the later Epicureanism was charged. (For the Cyrenaic hedonism, see ARISTIPPUS.) According to Epicurus, the sources and tests of all ethical truth are the feelings, and these are two, pleasure and pain. We delight in the one, and avoid the other instinctively. 'When we say that pleasure is the end of life, we do not mean the pleasures of the debauchee or the sensualist, as some from ignorance or from malignity represent, but freedom of the body from pain, and of the soul from anxiety. For it is not continuous drinkings and revellings, nor the society of women, nor rare viands, and other luxuries of the table, that constitute a pleasant life, but sober contemplation that searches out the grounds of choice and avoidance, and banishes those chimeras that harass the mind.' Epicurus rests justice on the same prudential basis as temperance. Denying any abstract and eternal right and wrong, he affirms that injustice is an evil, because it exposes the individual to disquietude from other men; justice is a virtue, because it secures him from this disquietude. The duties of friendship and goodfellowship are inculcated on the same grounds of security to the individual.
Among the Romans the system of Epicurus was adopted by many distinguished men. Horace, Atticus, and Pliny the Younger were Epicureans; Seneca, nominally a Stoic, drew much from Epicurus; and the great poem of Lucretius must have recommended the system to many. In modern times Epicureanism was resuscitated in France by Père Gassendi, who published an account of Epicurus's life and a defence of his character in 1647; and many eminent Frenchmen have professed his principles.
See ATOM, DEMOCRITUS, LUCRETIIUS; Zeller's Philosophy of the Stoics, Epicureans, and Sceptics (trans. by Reichel; new ed. 1880); W. Wallace, Epicureanism (1880); and monographs by Gizecki (Halle, 1879) and Kreibig (Vienna, 1885).