Epicurus’s successor in the direction of the Garden was Hermarchus of Mitylene, and he was succeeded in turn by Polystratus, who was the last survivor to have heard Epicurus. Superior to both, however, were Metrodorus and Colotes, against whom a small work by Plutarch was directed. Among the Epicureans of the 2nd century bce, mention must be made of Demetrius of Lacon, of whose works some fragments remain, and Apollodorus, who wrote more than 400 books. Much was also written by his disciple Zeno of Sidon, who was heard by Cicero in 79 bce in Athens. After Zeno, there were Phaedrus, also a teacher of Cicero, who was in Rome in 90 bce, and Patro, the head of the school until 51 bce. Already famous as an epigram writer was Philodemus of Gadara (born 110 bce). In the papyri of Herculaneum, comprising the effects of Philodemus’s library, there are sizable remains of almost all of his numerous works. Epicureanism had already been introduced in Rome, in the 2nd century bce. The first person to spread its doctrines in Latin prose was a certain Amafinius. At the time of Cicero, Epicureanism was in fact the philosophy in vogue; and the number of Romans subscribing to it was, according to Cicero, very large. Among the greatest was Titus Lucretius Carus (c. 95–55 bce), who, in the poem De rerum natura (On the Nature of Things), left an almost complete and amazingly precise exposition of Epicurus’s Physics. The extent to which Epicurus was still popular in the 1st century after Jesus is demonstrated by Seneca, who cited and defended him. To the 2nd century ce belongs Diogenes of Oenoanda, who carved Epicurus’s works on a portico wall. In the same century should perhaps be mentioned Diogenianus, fragments of whose polemic against the Stoic Chrysippus are found in the church historian Eusebius of Caesarea. Also Epicurean, between the 4th and 5th centuries, was the epigrammatist Palladas.

On account of its dogmatic character and its practical end, the philosophy of Epicurus was not subject to development, except in the polemic and in its application to themes that Epicurus either had treated briefly or had never dealt with at all. To be aware of this, it is sufficient to run through what remains of the representatives of his school and particularly of the works of Philodemus of Gadara. Epicurus’s philosophy remained essentially unchanged. Once truth has been found, it requires no more discussion, particularly when it completely satisfies the end toward which human nature tends. The main thing is to see this end; all of the rest comes by itself, and there is no longer anything to do but follow Epicurus, “liberator” and “saviour,” and to memorize his “oracular words.”

Epicureanism and egoism in modern philosophy

In the Middle Ages Epicurus was known through Cicero and the polemics of the Church Fathers. To be an Epicurean at the time of Dante meant to be one who denied providence and the immortality of the soul. In the 15th century, the notable humanist Lorenzo Valla—following brief hints by Petrarch—wrote, in the dialogue De voluptate (1431; On Pleasure), the first modern defense of the ethics of Epicurus, maintaining that the true good is pleasure and not virtue but concluding that the supreme pleasure is that which awaits humans in heaven, which even the Bible calls paradisum voluptatis. In the 16th century, in terms of attitude and direction of thought, the first two great Epicureans were Michel de Montaigne in France and Francesco Guicciardini in Italy. Epicurean in everything, as human being and as poet, was the early 16th-century classicist Ludovico Ariosto. But not until the 17th-century Provençal abbot Pierre Gassendi was the system of Epicurus to rise again in its entirety—this time, however, by approaching truth through faith. Gassendi in 1649 wrote a commentary on a book by the 3rd-century-ce biographer Diogenes Laërtius. This comment, called the Syntagma philosophiae Epicuri (Treatise on Epicurean Philosophy), was issued posthumously at The Hague 10 years later. At the same time, in England, Thomas Hobbes, a friend of Gassendi, took up again the theory of pleasure and interpreted it in a dynamic sense, which was therefore closer to the doctrine of the ancient Cyrenaics. Starting from the premise that, in the natural state, “man is a wolf to man,” he concluded that peace, without which there is no happiness, cannot be guaranteed by anything but force, and that this force must be relinquished, by common agreement, to the power of only one.

During the 17th and 18th centuries, the European nation in which Epicureanism was most active was France, where its representatives were called libertines, among them moralists such as François, duc de La Rochefoucauld, and Charles de Saint-Évremonde; scientists such as Julien de La Mettrie, who believed that humans could be explained as machines, Claude-Adrien Helvétius, who reduced the ethic of the useful to a form of experimental science but who put public above private well-being, and Paul Henri Dietrich, baron d’Holbach, who gave particular importance to the physics of the atoms. The purely sensate conception of knowledge had its most thoroughgoing theoretician in Étienne Bonnot de Condillac. In England, Adam Smith, developing the ethical concepts of David Hume (founded on sympathy), surmounted the egoism that is the basis of every act by using the principle of the impartial observer invoked to sympathize with one or another of the antagonists. After him, the jurist Jeremy Bentham, eliminating sympathy, reduced ethics to the pure calculus of the useful, which—in an entirely Epicurean formula—he defined as a “moral arithmetic.” In the Epicurean stream lay also the utilitarianism of the 19th century, of which the greatest representative was John Stuart Mill.

Epicureanism in later philosophy

In the 19th century, the interpretation of pleasure as a psychic principle of action was initiated by Gustav Theodor Fechner, the founder of psychophysics, and developed toward the end of the century by Sigmund Freud on the psychoanalytic level of the unconscious. Epicureanism and egocentric hedonism had few faithful representatives among 20th-century philosophers, though the viewpoint remained as a residue in some strains of popular thinking.