(b. Italy, ca. 95 B.C.; d. ca. 55 B.C.), natural philosophy.
Lucretius followed the Epicurean maxim “Live unnoticed” so well that almost nothing is known for certain about him. His “poemata” were known to Cicero and his brother in 54 B.C.1 St, Jerome reports that he was born in 94 (or 93 or 96, according to other manuscripts), that he was driven mad by an aphrodisiac, that in the intervals between fits of madness he wrote several books, which Cicero afterwards edited or corrected (emendavit), and that he took his own life at the age of forty-four.2 In the life of Vergil attributed to Donatus, it is said that Lucretius died on the same day that Vergil took the toga virilis, but the date of this event is stated ambiguously and may be either 55 or 53.
Lucretius was probably a Roman, and probably of aristocratic family, although other views have been advanced. His only work, the poem De rerum natura, shows familiarity with Roman life and with Roman literature. It is written for “Memmius,“probably C. Memmi us, a Roman aristocrat who was praetor in 58 B.C. and later governor of Bithynia. The poem is written in Latin hexameters and divided by the poet into six “books.“The title itself is a translation of ∏∊pį ϕúσ∊ωs, the name of many Greek works of natural philosophy, including a hexameter poem by Empedocles and a long prose treatise by Epicurus, of which only mutilated fragments survive. There is some indication that the poem was not finished—there are repetitious passages (although some may be deliberate), some books are more polished than others, and the end of book VI does not seem to be the intended end of the whole poem.
Books I and II contain an exposition of the elements of the atomic theory. Books III and IV are about the soul. Book V, which is the longest, describes the origin of the cosmos and the natural growth of living creatures and of civilization. Book VI is on sundry natural phenomena of the sky and earth.
The core of Epicurean natural philosophy is given in books I, II, and V, and there are signs that these were the first books in order of composition. There is some correspondence between the order and proportion of these three books and Epicurus“outline of the subject in the extant Letter to Herodotus. In the absence of Epicurus’ major work, On Nature, it is impossible to say how closely Lucretius follows him, but there is perhaps little or nothing in the natural philosophy of Lucretius that was not in that of Epicurus: The poem shows astonishingly little consciousness of such post-Epicurean philosophies as Stoicism. The Italian imagery and the animadversions on Roman life and morality are no doubt Lucretius’ own.
The existence of this long poem on the Epicurean world picture is surprising in itself. The extant work of Epicurus shows a prosaic mind; and the rather impoverished utilitarianism that he taught gives little obvious encouragement to a poet, although there is evidence that Epicureans were interested in poetry and music in the fragments of work by Lucretius contemporary Philodemus. But for all one knows, it was lonely poetic genius that produced this poem–one of the greatest in the Latin language.
If one compares Lucretius’ poem with the extant writings of Epicurus and with the general picture of Epicurus’ philosophy given by ancient critics, certain changes of emphasis are noticeable. Lucretius devoted two whole books, set in the middle of the exposition of the atomic cosmology, to the structure and functions of the soul—a much higher proportion than in Epicurus Letter to Herodotusy’. Theory of knowledge or “canonic“received little attention from Lucretius. Moreover, the moral lessons, although they are certainly not omitted, occur mainly in the introductions to each book, or in the form of satire on Roman life; there is little preaching in the manner of Epicurus’ Letter to Menoeceus. For all these differences, the De rerum natura remains purely Epicurean in that the acknowledged motive is not disinterested scientific curiosity, but peace of mind.
Lucretius’ atomic theory can be understood best by comparing it with the world picture of Plato and Aristotle. In contrast with the finite, single world of Platonic and Aristotelian theory, later adopted by Christian philosophers, the atomists argued that the universe is infinitely large and contains an unlimited number of cosmoi, past, present, and future.3 The single Aristotelian cosmos was without beginning or end in time; there was thus no problem for Aristotelians about the origin of its parts and of their order. The atomic theory, on the other hand, was committed to explaining the origin of everything in the world. Atoms and void were ungenerated and indestructible, but the earth, sea, air, and stars were compounds that came into being at a particular time; their origin had to be explained.
Plato and Aristotle preferred teleological explanations in their natural philosophies. Plato’s Timaeus offers some grounds for this preference in the notion that the cosmos was created by an intelligent craftsman; the Christian world picture was similar in this respect. Aristotle’s eternal cosmos had no creator; the evidence of order and design showed that the cosmos is an ordered whole, but did not point to a designer. Epicurean atomism rejected this teleology, and sought to explain everything by mechanical causes.4 It was therefore necessary to find plausible explanations for apparently purposive or highly ordered phenomena, and some of Lucretius’ most earnest arguments were devoted to this end. The hypothesis of the infinity of the universe was a vital premise in these arguments: in infinite time an infinite supply of atoms moving in infinite space will produce everything that atoms can possibly produce by their coin binations.5
The theory held that all atoms are too small to be perceived individually. They are all made of the same material, and have no properties other than shape, size, and weight; their weight is the cause of their natural motion downward through the void. This motion could be interrupted by two causes: an unexplained swerve (clinamen)—postulated by Epicurus to explain the formation of compounds and to free the movements of the soul from “fate“—and collisions with other atoms.6 The perceptible qualities of compounds were explained by relating them to atomic shapes and to the proportion of void in the compound, Atoms in compounds move continually, with very frequent collisions in dense compounds, but more freely in compounds containing a greater proportion of void.7
Lucretius presented a simple causal theory of perception: all compounds throw off “films” of atoms (simulacra) from their surfaces, and these somehow mark their pattern on the soul atoms by direct contact.8 The soul itself is a mixture of atoms of four kinds—something like heat, something like pneuma, something like air. and a fourth unnamed kind.9 All the soul atoms are highly mobile, but they are not themselves alive; like other atoms they possess no properties other than shape, size, and weight.10 At death they simply disperse into the air (the theory so confidently rebutted in Plato’s Phaedo, 70a ff.).11
Book V of Lucretius’ poem puts the elements of the atomic theory into action, so to speak, to show how the cosmos and all things in it originated from atoms moving in the void, without any divine plan or direction. First the world masses were formed, then the earth began to grow vegetation spontaneously, and finally animal species also emerged from the earth. Once having come from earth, a species survived if it were so adapted as to nourish and reproduce itself; otherwise it simply died out as soon as the earth, growing old, ceased to be spontaneously productive. (The theory thus includes the origin of species and the survival of the fittest, but not the evolution of the species.) It was this account of the natural origin of everything, denying Providence and divine creation, that, along with the denial of the survival of the soul, most antagonized Christian philosophers.12
The fatal weakness of the ancient atomic theory, considered as a framework on which to build explanations of natural phenomena, was that it could not offer any laws describing the elementary interactions of atoms. The whole theory depended on the effects of shape, size, and weight of atoms when they collided with each other; but the mechanics of the theory relied on simple intuitions and analogies, such as the vague principle of “like to like” taken over from Democritus. In the ancient world the teleological explanation adopted by Platonists, Aristotelians, and Stoics was clearly more satisfying, especially in biology.
During the early part of the Christian era, Lucretius was first attacked for denying Providence, then, later, forgotten except by grammarians and lexicographers. His poem may have been known in Padua in the thirteenth century,13 but it was Gian Francesco Poggio’s rediscovery of a manuscript early in the fifteenth century that began the great revival of interest in his work. Both the anti-Aristotelian cosmology and the beauty of Lucretius’ poetry attracted writers of the Italian Renaissance. Ficino studied him, but rejected his doctrines. Bruno found support in Lucretius’ doctrine of the infinite universe and plurality of worlds, and wrote Latin poems in imitation of him. With the full revival of atomism in Western Europe, especially as manifested by Gassendi. it became harder to distinguish the influence of Lucretius from that of Democritus, who was known mainly through Aristotle’s polemics, and from that of Epicurus.
1. Cicero, Ad Q. Fratrem, 2, 9, 3.
2. St Jerome, on Eusebius’ Chronicle 94.
3.De rerum natura, I, 951-1082; II, 1023-1089.
4.Ibid., IV, 822–876; V, 110–234.
5.idbi.,, I, 1021–1051; II, 1058–1063; V,419–431.
6.Ibid., II, 62–293.
7.Ibid., II, 332–521; 730 864.
8.Ibid., IV, 26–857.
9.Ibid., Ill, 177–369.
10.Ibid,, II, 865–1022.
12. E.g., Lactantius, De ira dei, 10.
13. Billanovich, “Veterum vestigia vatum.”
I. Original Works. The editio princeps of De rerum mtura was that of T. Ferrandus (Brescia, 1473). The best modern English ed. is that of C, Bailey (Oxford, 1947, repr. with corrections, 1949), although the commentary is weak on philosophical matters. Other particularly interesting eds. are those of H. A. J. Munro (Cambridge. 1864) and C. Giussani (Milan, 1896–1898). There is a useful commentary by A. Ernout and L. Robin (Paris, 1925–1926). A reliable but dull English trans, in prose is that of R. E. Latham (Harmondsworth, 1951); a more exciting one, in verse, is by Rolfe Humphries, deplorably entitled Lucretius; The Way Things Are(Bloomington, Ind., 1968).
II. Secondary Literature. E. Bignone, Storia della letteratura Latino, II (Florence, 1945), 456–462; and C. Bailey and D. E. W. Wormell in M. Platnauer, ed., Fifty Years (and Twelve) of Classical Scholarship (Oxford, 1968) contain good secondary bibliographies.
On Lucretius as a natural philosopher see V. E. Alfieri, Atomos Idea (Florence, 1953); Anne Amory, “Obscura de re lucida carmina: Science and Poetry in De Rerum Natura,” in Yale Classical Studies, 21 (1969), 145–168; C. Bailey, The Greek Atomists and Epicurus (Oxford. 1928; repr. New York, 1964); and E. Bignone, cited above. Also see G. Billanovich, “Veterum vestigia vatum,” in Italia Medioerale e Unranistica, 1 (1958), 155–243: P. Boyanee, Lucrece et l’Epicurisme (Paris, 1963); P. De Lacy, “Limit and Variation in the Epicurean Philosophy,” in Phoenix, 23 (1969), 104–113; and D. R. Dudley, ed., Lucretius(London, 1965; seven essays by different authors), B. Farrington’s Science and Politics in the Ancient World (London, 1935) was reviewed by A. Momigliano in Journal of Roman Studies (1941), 149 ff.
Other studies include D. J, Furley, “Lucretius and the Stoics,“in Bulletin of the Institute of Classical Studies,13 (1966), 13–33; and “Variations on Themes From Empedoeles in Lucretius’ Proem,“ibid., 17(1970), 55–64; G. D. Hadzits, Lucretius and His influence (Sew York, 1935); Gerhard Miiller, Die Durst elhmg dcr Kinetik bet Lukrez (Berlin, 1959); G. Santayana, Three Philosophical Poets: Lucretius, Dante and Goethe (Cambridge, 1910); F. Solm-sen, “Epicurus and Cosmological Heresies,“in American Journal of Philology,62 (1951), 1 ff.; “Epicurus on the Growth and Decline of the Cosmos,” ibid., 64 (1953), 34 ff.; and W. Spoerri, Spdthellenistische Berichte fiber Welt, Kultur find Cotter (Basel, 1959)
David J. Furley
Lucretius (ca. 94-ca. 55 B.C.), full name Titus Lucretius Carus, was a Latin poet and philosopher. His one work, De rerum natura, a didactic poem in hexameters, renders in verse the atomistic philosophy of Epicurus, forerunner of the modern-day atomic theory.
Almost nothing is known of the life of Lucretius. The medieval chronicler Jerome is the only source of information. After giving his subject's birth date, Jerome declares that Lucretius was made insane by a love potion and composed his poetry during intervals of lucidity, with later emendations by Cicero. Lucretius committed suicide, according to Jerome, in the forty-fourth year of his life (50 B.C.)
Despite Jerome, the date of Lucretius's death is more commonly assigned to 55 B.C., because Donatus, the 4th-century biographer of Virgil, says that the poet assumed the toga of manhood on the very day Lucretius died. Cicero also comments in a letter to his brother Quintus in 54 B.C. that "The poems of Lucretius are, as you say in your letter, touched by flashes of genius and all the same composed with great skill." It is assumed that Cicero would have had Lucretius's poem in hand only after the letter's death. If Jerome is correct as to Lucretius's age at death (44 B.C.) and Donatus as to the year, the poet was born in 99 B.C.
Lucretius is generally considered to have belonged to one of Rome's old aristocratic families, although some scholars have concluded from the name Carus that he was a slave in a Lucretian household or, at best, a freedman.
As to the story of Lucretius's insanity from a love potion, it is supported by a passage at the end of book 4 of De rerum natura (On the Nature of the Universe) in which the poet violently attacks the lovemaking of men and women—which he describes rather fully. No other direct or indirect evidence exists. The work itself is dedicated to Memmius, a patron of literature who dabbled in verse. Memmius was a Roman magistrate in 58 B.C. and afterward governor of the province of Bithynia.
De rerum natura, some 7,400 lines long, is divided into 6 books. The title translates the Peri Physeos of Epicurus, whom Lucretius acknowledges as his master and praises in the most lavish terms.
Book 1 begins by invoking Venus, appealing to Memius, praising Epicurus, and listing the wrongs committed in the name of religion, the reasons for accepting Epicurus, and the difficulty of treating Greek philosophy in Latin verse. Next, the poet sets forth the atomic theory of Epicurus (derived from Democritus). Nothing comes from nothing and nothing can be destroyed. Matter exists in imperceptible particles (atoms) separated from one another by space. The atoms are solid, indivisible, and eternal. Lucretius then refutes the rival systems of Heraclitus, Empedocles, and Anaxagoras and proves that the universe is infinite and that its two components are also infinite, atoms in number, space in extent.
Book 2 contains Lucretius's most explicit reference to the moral theory of Epicurus. It also deals with the motion of the atoms, maintaining that their "slight swerve" (exiguum clinamen, book 2: line 292) causes free will. Lucretius passes to the shape of the atoms and the effects their various forms create. The number of shapes is not infinite, but the number of any given shape is. The atoms lack secondary qualities, that is, color, heat, and sound, and are without sensation. Finally, Lucretius shows that there is an infinite number of worlds and describes their formation and destruction.
Book 3 treats of the soul, its nature, composition, and fate. In the first two books Lucretius's purpose is to dispose of human fear of the intervention of gods into the world by proving that the universe is material and all events are due to the movement and combination of atoms. In book 3 he counteracts the fear of death and of punishment after death by proving that the soul, too, is composed of matter and is dissolved at death into atoms. The book ends with a triumphant passage on the mortality of the soul and the folly of the fear of death.
In book 4 the poet deals with the nature of sensation and thought: sight is the result of emanations of atoms from an object which pass into the eye. The remaining senses and the mental processes function in an analogous way. Next, the poet refutes the teleological view of creation, treats of the will, sleep, and dreams, and ends the book with a violent attack on the passion of love (which makes men do unreasonable things).
Books 5 and 6 are an appendix in which the atomic principle is applied in detail. Book 5, after praise of Epicurus and an attack on the religious view, describes the beginning and end of this world and certain problems of astronomy. The poet then accounts for the origin of life on earth, the creation of man, and the development of civilization.
Book 6 begins with a eulogy to Epicurus. It deals with miscellaneous celestial and terrestrial phenomena and proves that they have physical causes, thus opposing popular superstition, which interpreted unusual occurrences as divine signs. A treatment of pestilences leads him to a long (150 lines) description of the plague at Athens in 430 B.C. on which the work closes.
Throughout his work Lucretius attacks religion and the fear of death, for him the causes of all evils on earth. He upholds the powerful light of intellect, which has discovered the true nature of the universe. Specifically, it is Epicurus who, through the "living force of his mind" (1:72), penetrated beyond the "flaming walls of heaven," traversed the measureless universe in his imagination, and then set forth what can and cannot come into being and how each thing has its powers limited (1:62-79).
Religion, says Lucretius, has been responsible for such monstrous acts as the sacrifice at Aulis of the pitiful Iphigenia, young daughter of King Agamemnon. The fear of death and of punishment after death is the cause of avarice, ambition, cruelty, and other forms of wickedness. This fear can be dispelled only by an understanding of the "outer appearance and inner working of nature" (3:31-93). Lucretius maintains that it is necessary to use the charm of poetry to explain the nature of the universe just as doctors, when attempting to persuade children to drink bitter medicine, smear the rim of the cup with honey (1:933-950, 4:6-25).
Liberated by philosophy from superstitious fears and the fear of death, man achieves ataraxia, a state in which he is free of disturbances of all kinds. He has gained, Lucretius says, a lofty and serene sanctuary, well fortified by the teaching of the wise, from which he may view others in their futile struggle to reach the top in human affairs.
The fervor of Lucretius's arguments, especially the violence of his attack on love at the end of book 4, does not seem to stem from a completely tranquil mind. Yet his poetry is at times magnificent, his hexameters, although not as lithe and graceful as Virgil's, have a powerful and austere majesty. Above all, Lucretius's effort to free men, by science and the power of intellect, from the dark and irrational fears which enslave and torture them has earned him a place among the benefactors of humankind.
Works on Lucretius include George Santayana, Three Philosophical Poets: Lucretius, Dante and Goethe (1910); George D. Hadzsits, Lucretius and His Influence (1935); E. E. Sikes, Lucretius, Poet and Philosopher (1936); Henri Bergson, The Philosophy of Poetry: The Genius of Lucretius, edited and translated by Wade Baskin (1959); Alban D. Winspear, Lucretius and Scientific Thought (1963); Donald R. Dudley, Lucretius (1965); and David West, The Imagery and Poetry of Lucretius (1969). □
Roman poet and philosopher; b. c. 98 b.c.; d. 55 b.c. Lucretius was probably an aristocrat and a friend of Gaius Memmius, the patron of Catullus and Cinna. According to St. Jerome, he composed his only poem, De rerum natura (On the Nature of the Universe), in the lucid intervals between bouts of insanity, and he died by his own hand, the unfinished poem being entrusted to Cicero for publication. Yet Lucretius was a poet of great ability and forged a strong link in the chain of Latin hexameter verse between Ennius and Vergil. His poem had earlier models in the works of Xenophanes, parmenides, and especially empedocles ("On Nature"). Indeed, the opening invocation to "kindly Venus" who alone has power to subdue Mars, the god of war, may refer to a wish not only for the end of civil strife in Rome, but also for the reconciliation of the cosmic forces of love and strife found in Empedocles.
The general aim of the poem is the elimination of superstitious fear—whether of the gods, unusual happenings, or death—by an account of nature that will be rational and will exclude any divine interference. Thus the poet's main purpose coincides with that of the epicureanism he professed. In a word it is ethical: it aims at tranquillity and peace of mind. However Lucretius does concentrate upon that division of Epicureanism called physics or philosophy of nature. No capricious agency, but the movement of atoms, eternally falling through the void, accounts for everything. The introduction of an arbitrary swerve (the ultimate source of man's free will) enables them to unite by collision, rebound, and interlinkage. Considerable ingenuity is shown in the naturalistic accounts of the origin of the world, heavenly bodies, man, and speech. Further it is argued that the mind or soul is also corporeal, being composed merely of finer atoms than body, and therefore, equally liable to dissolution. Knowledge comes about through material contact with the effluences or images that are constantly being given off by all things. Explanations of portents and extraordinary phenomena are provided in order to rid the mind of vain fears.
Perhaps, in his lengthy treatment of the emotion of love, Lucretius is speaking from personal experience. He is well aware that it is a pleasure not unmixed with pain and a desire that is sharpened rather than allayed by the attempt to satisfy it. Here he shows evidence of Epicurus's refined critique of pleasure. Man needs to live a life of peace with his soul purged alike from fear and vice, thus imitating the eternal peace and freedom from emotion of the gods, from whom come emanations that announce divine tranquillity.
The attitude of Christians toward Lucretius has been somewhat ambivalent. Early Christian writers, such as arnobius and lactantius, although opposed to Epicureanism, borrowed much from Lucretius and even made use of his attacks against the pagan gods. But medieval manuscripts of his work are rare, and the few copies made from one fourthor fifth-century original seem to owe their existence to the Carolingian literary revival. From the Renaissance onward greater interest was shown, and several printed editions appeared. Although valued as a poet, Lucretius was still opposed on doctrinal grounds; witness the Anti-Lucretius of Cardinal Melchior de polignac—nine books of hexameter verse De Deo et Natura (On God and Nature), published in Paris in 1747. Since the nineteenth century, however, Lucretius has been studied sympathetically by many Christians.
Lucretius appears as a sensitive man of genius whose aim was to banish from human life the craven fear of deities, unreasoning terror at so-called supernatural phenomena, and anxiety over death. It is incorrect to call him either an atheist or a hedonist in the normal sense of these terms. His end was tranquillity of soul, a tranquillity that he himself perhaps never achieved. It is the Epicurean doctrine of the noninvolvement of deity within man's world that leads to the mechanistic materialism that he so skillfully describes in hexameter verses of great power and even beauty. Such a viewpoint seemed to him vastly superior to the rank superstition that characterized much so-called religion in the first century b.c. Lucretius excites sympathy as a noble character in an evil world; he never lived to see the advent of a religion characterized by a relationship of love and trust between God and man.
See Also: atomism; materialism.
Bibliography: Works. De rerum natura, ed. and tr. c. bailey (Oxford 1947); ibid., tr. w. h. d. rouse (Loeb Classical Library London-New York-Cambridge 1912); Titus Lucretius Carus on the Nature of Things, tr. t. jackson (Oxford 1929); Lucretius on the Nature of Things, tr. r. latham (Baltimore, Md. 1957). Literature. c. a. gordon, A Bibliography of Lucretius (London 1962). a. d. winspear, Lucretius and Scientific Thought (Montreal 1963). h. hagendahl, "The Apologists and Lucretius," pt.1 of Latin Fathers and the Classics (Göteborg 1958). l. alfonsi, Enciclopedia filosofica, 4 v. (Venice-Rome 1957) 3:187–190.
[w. h. o'neill]
ROMAN NATURAL PHILOSOPHER
ca. 95 b.c.e.–ca. 55 b.c.e.
Little is known about Titus Lucretius Carus beyond what can be gathered from his poem De rerum natura. He was born in about 95 b.c.e., but the exact date is uncertain. The exact date and circumstances of his death are also uncertain, but he probably died in or before the year 55 b.c.e. We do know from his poem that he believed the teachings of the Greek atomists, ranging from those of Democritus of Abdera (ca. 460 b.c.e.–ca. 362 b.c.e.) to those of Epicurus (ca. 341 b.c.e.–270 b.c.e.). Unlike the writings of Democritus or Epicurus, Lucretius's poem was one of the few literary works not lost to European peoples after the collapse of the classical world.
De rerum natura is a poem in the Latin language that gives a summary of the teachings of the Greek atomists. His starting point is a reliance on direct human experience of the natural world. From this starting point he reasons: "Nothing can ever be created by divine power out of nothing" (Lucretius, p. 31). Accordingly, if something could be created out of nothing, things would pop in and out of existence without any pattern at all. From that deduction Lucretius develops a philosophy that does not allow for occult forces, superstition, or magic. Beliefs such as these were pervasive in the Roman world during his lifetime. That philosophy also clearly sets "atomism" against any sort of theistic religion. This religious antagonism would continue to plague atomic theories until the modern era.
According to Lucretius: "All nature as it is in itself consists of two things—bodies and the vacant space in which the bodies are situated and through which they move in different directions" (p. 39). He addresses the question of the immense variety of material things found in nature by recognizing that there must be some way for atoms to combine and at the same time maintain their individual characters: "Material objects are of two kinds, atoms and compounds of atoms. The atoms themselves cannot be swamped by any force, for they are preserved indefinitely by their absolute solidity" (p. 41). Lucretius does not suggest that we directly experience atoms. He makes no claims as to the shapes of atoms or any other of their characteristics.
see also Atoms.
David A. Bassett
Lucretius (1951, reprint 1977). On the Nature of the Universe, tr. by Ronald Latham. New York: Penguin Books.
Lucretius (Titus Lucretius Carus) (lōōkrē´shəs), c.99 BC–c.55 BC, Roman poet and philosopher. Little is known about his life. A chronicle of St. Jerome speaks of the loss of his reason through taking a love potion. It states that in sane intervals he had written books that were later emended by Cicero. The poetry of Lucretius constitutes one great didactic work in six books, De rerum natura [on the nature of things]. In dignified and beautiful hexameter verse the poet sets forth arguments founded upon the philosophical ideas of Democritus and Epicurus. He seeks to persuade man that there need be no fear of the gods or of death, since
"man is lord of himself."
His proof is based upon the so-called atomic theory of the ancients, which held that everything, even the soul, is made up of atoms, and the laws of nature control all. The soul is itself material and so closely associated with the body that whatever affects one affects the other. Consciousness ends with death. There is no immortality of the soul. The universe came into being through the working of natural laws in the combining of atoms, instead of by the creative power of a deity. Although not the same as the modern atomic theory, many of the principles he gives in his scientific discussions have been upheld by later investigations.
See the translation by C. Bailey (3 vol., 1947); studies by L. A. Holland (1979) and D. Clay (1983); S. Greenblatt, The Swerve (2011).