On the Nature of Things, written around 59 to 55 BCE , is an epic poem written in Latin, in dactylic hexameter, whose theme is the universe and everything in it, including human beings. Little is known about its author, Titus Lucretius Carus (known commonly as Lucretius). He is the main source for understanding Epicurean physics, which is based on a theory of the indivisible atom, that is both birthless and deathless. The Epicureans argued that unless the elements of nature were indivisible and indestructible, there could be no permanence for the universe (Martin Ferguson Smith, Introduction p. XXVI) All atoms are always in motion, with those moving freely through the void falling downward by reason of their weight. “But sometimes,” wrote Lucretius, “at uncertain times and places (incerto tempore, incertisque locis) , the eternal, universal fall of the atoms is disturbed by a very slight deviation - the "clinamen" (2.216 -292).” The resulting vortex gives rise to the world of compound bodies, to all natural things. (For Gilles Deleuze, incertus does not mean indeterminate, but rather unassignable. It occurs in an interval smaller than the minimum of continuous, thinkable time.)

The clinamen is also translated as "swerve." Lucretius attributes both the creations of nature and the creations of mind to the clinamen. According to Michel Serres, it should not be treated as an occasional “chance” event, but rather as the theoretical expression of an irreducible complexity in the order of events. For Lucretius, It is also the source of free will.  "The fact that the mind itself has no internal necessity to determine its every act and compel it to suffer in helpless passivity--this is due to the slight swerve of the atoms at no determinate time or place."  (2.292)

 "Again, if all movement is always interconnected, the new arising from the old in a determinate order -- if the atoms never swerve so as to originate some new movement that will snap the bonds of fate, the everlasting sequence of cause and effect -- what is the source of the free will possessed by living things throughout the world?" Lucretius, De Natura Rerum, Book II.


          No atoms, casually together hurl'd

          Could e'er produce so beautiful a world.

          Nor dare I such a doctrine here admit,

          As would destroy the providence of wit. --Dryden


On the Nature of Things is an extraordinary fusion of poetry and philosophy. Lucretius compares the relation between his poetry and the philosophical ideas to coating a bitter medicine with sweet honey, although this does not do justice to the poem.  (1.921-950)

While Lucretius’ epic poem is the main written link to Greek Epicurean philosophy, the text itself was lost for more than a thousand years -- before an Italian Humanist, Poggio Bracciolini, discovered a manuscript in 1417, in a German monastery. Steven Greenblatt’s book The Swerve recounts the rediscovery of the text, its role in the Renaissance and the challenges it posed to right-thinking Christian orthodoxy. (He was usually considered an atheist.) Greenblatt’s subtitle is “How the World became Modern”. `

 What is the relation of On the Nature of Things to modern science?

“Everyone knows”, writes Michel Serres at the beginning of The Birth of Physics, that atomist physics is an ancient doctrine but a contemporary discovery…(and) the ancient doctrine is only ‘philosophy’ or even poetry. (p. 21) Serres’ project is to look at the declination of atoms, not as part of the “prehistory” of science, but as a treatise on physics.

Although many of its ideas resemble modern scientific ones (such as the focus on atoms), the ideas form a “theory” that seeks a material basis, even if it is unobservable. The theory is reasoned, if not “scientific”, and is developed through logical arguments. It is naturalistic — it claims to be realized in the world — and explores only natural causes. This account does not appeal to the gods -- according to Lucretius the gods are not interested in human life – and it accepts absolute limits, such as death (of both body and soul) as the conditions for establishing and ethics of naturalism.

This focus on physical (and physiological) cause leads to some shocking and unexpected arguments, for example in relation to sex and love. Lucretius describes sex as natural and healthy part of life, one that humans share with animals. But he considers love, which is based on a fantasy of complete fusion and endless happiness, as an affliction, as an illusion and a creation of the mind. As a source of frustration and unhappiness love is contrary to the Epicurean goals of pleasure. Just like the acceptance of the finality of death, the Epicurean accepts limits as both an ethical duty and source of pleasure.

For Michel Serres, the clinamen is" the minimum angle to the laminar flow that initiates a turbulence." (Serres, Hermes, p.99) In a laminar flow, however small the laminae cut from the flow may be, the movement of each is strictly parallel to the movement of others. The clinamen is the smallest imaginable condition for the original formation of turbulence, a vortex (tourbillon) appearing by chance in a laminar flow. It is a deviation that occurs spontaneously, with no cause and no end. It is the condition for atoms to meet and combine and thereby for the emergence of order. Crucial to Serres reconception of the Atomists' thought is a recognition that their model of atomic matter is essentially a fluid one - they are describing the actions of turbulence, which impacts our understanding of the recent disciplines of chaos and complexity. “And who can fail to see that a laminar flow is merely ideal and theoretical?” For Serres, “Laminar flow, the figure of chaos, is at first sight a model of order.” (p.43) He calls it the “first chaos”, the absence of order in perfect order.” (p.4)

 Ilya Prigogine refers to Michel Serres' studies of Lucretius and links the clinamen to the attempt to explain turbulence. (from Prigogine and Stengers, Order out of Chaos p.141 ) Presumably, Prigogine's "fluctuations" are instances of the clinamen. (see bifurcation) (see also self-organization)  and cf "sensitivity to initial conditions" One reason why the clinamen seems relevant to the new sciences is that it is too small and too short-lived to be perceptible. While this might disqualify it from the physics of sold bodies, it is much more relevant to a physics of fluids.

 For Jean Laplanche, the transformation of the functions of instinct into sexuality is a clinamen.The clinamen  is the operator that marks the passage from the theoretical to the practical: it is the birth of existence.

 In general, what is a form? Answer: some smooth plus some folds (Serres, Atlas,p.48)


Luccretius, On the Nature of Things, translated, with an introduction by Martin Ferguson Smith. Hackett Publishers, 1969. Steven Greenblatt, The Swerve: How the World Became Modern, W.W.Norton, 2011. R.D Brown, Lucretius on Love and Sex. Selection accessed at: Brooke Holmes, “Deleuze, Lucretius, and the Simulacrum of Naturalism”, in: Dynamic Reading: Studies in the Reception of Epicureanism edited by Brooke Holmes, W. H. Shearin. For further research: Michel Serres, The Birth of Physics, Rowman & Littlefield International, 2018.