The Swerve: How the World Became Modern

by Stephen Greenblatt

What human beings can and should do, he wrote, is to conquer their fears, accept the fact that they themselves and all the things they encounter are transitory, and embrace the beauty and the pleasure of the world.

“swerve,”—Lucretius’ principal Latin word for it was clinamen—an unexpected, unpredictable movement of matter.

• The universe has no creator or designer. The particles themselves have not been made and cannot be destroyed. The patterns of order and disorder in the world are not the product of any divine scheme. Providence is a fantasy. What exists is not the manifestation of any overarching plan or any intelligent design inherent in matter itself. No supreme choreographer planned their movements, and the seeds of things did not have a meeting in which they decided what would go where. But because throughout the universe from time everlasting countless numbers of them, buffeted and impelled by blows, have shifted in countless ways, experimentation with every kind of movement and combination has at last resulted in arrangements such as those that created and compose our world. (1.1024–28)

• Everything comes into being as a result of a swerve. If all the individual particles, in their infinite numbers, fell through the void in straight lines, pulled down by their own weight like raindrops, nothing would ever exist. But the particles do not move lockstep in a preordained single direction. Instead, “at absolutely unpredictable times and places they deflect slightly from their straight course, to a degree that could be described as no more than a shift of movement.” (2.218–20) The position of the elementary particles is thus indeterminate. The swerve—which Lucretius called variously declinatio, inclinatio, or clinamen—is only the most minimal of motions, nec plus quam minimum. (2.244) But it is enough to set off a ceaseless chain of collisions. Whatever exists in the universe exists because of these random collisions of minute particles. The endless combinations and recombinations, resulting from the collisions over a limitless span of time, bring it about that “the rivers replenish the insatiable sea with plentiful streams of water, that the earth, warmed by the sun’s fostering heat, renews her produce, that the family of animals springs up and thrives, and that the gliding ethereal fires have life.” (1.1031–34) • The swerve is the source of free will. In the lives of all sentient creatures, human and animal alike, the random swerve of elementary particles is responsible for the existence of free will. For if all of motion were one long predetermined chain, th...

an outside force may strike against a man, that man may deliberately hold himself back.

• Nature ceaselessly experiments. There is no single moment of origin, no mythic scene of creation. All living beings, from plants and insects to the higher mammals and man, have evolved through a long, complex process of trial and error.