I very much enjoyed The Swerve, but perhaps only because I have acquired a talent for ignoring large swathes of what Renaissance scholars say about the Middle Ages. Greenblatt seems to think that medieval Europe was largely populated by monks whose favorite pastime was whipping themselves, when they weren't being slaughtered by barbarians. On the other hand the angry responses of medievalists are just as silly, like a certain Jim Hinch whose rage against Greenblatt inspires him to insist that
Western civilization was created in medieval Europe. The forms of thought and action which we take for granted in modern Europe and America. . . . and from which indeed we cannot escape, were implanted in the mentalities of our ancestors in the struggles of the medieval centuries.I will leave this wrathful sputtering to people who enjoy shouting past each other and move on to more important things. Because whatever Jim Hinch says, the modern world is very different from the medieval one, and it must have gotten that way somehow. How?
De Rerum Naturae -- "The Way Things Are" in the usual English translation -- describes in lovely Latin verse the philosophy we know as Epicureanism. The philosophy of Epicurus has two distinct but related parts, a physics and a guide to life. The physics is atomism. Atomism means, first, that the world is made of tiny particles, and all the phenomena we observe are created by atoms moving about (the "swerve") and combining with each other; second, that the motions of atoms explain everything about the universe, which therefore has no need of gods, spirits, or immaterial souls. Atomism was the creation of Democritus, a Greek thinker of the fifth century BCE. Epicurus, who lived 150 years later, thought that he had extracted the practical lesson of atomism: since there is nothing in universe but atoms and void, and therefore no gods, commandments, or divine judgment, the best we can do with our lives is to seek out pleasure and avoid pain. This philosophy was a dangerous one to even discuss in the fifteenth century and fatal to advocate publicly, yet the age could not resist Lucretius. Every intellectual seems to have read him, from skeptics to ardent believers like Thomas More, whose Utopia is a sophisticated response to Epicurus. So this book, radically anti-Christian in both style and substance, full of the most dangerous possible ideas, somehow managed to spread across Europe at the height of the Protestant and Catholic Reformations; Greenblatt explains that it was left off the first Catholic index of forbidden books because the head of the Inquisition was a fan.
Greenblatt's discussion of Lucretius' wide reception is not likely to cause much controversy, because it is mainly a narrative of well-documented events. Since I do not have much interesting in debating how dark the dark ages were, to me the most interesting question raised here is how much influence this book or any other book can have on the course of history. I usually finish books like The Swerve thinking that the author has grotesquely exaggerated the importance of his subject; don't get carried away, I want to say to the average historian. But in this case I think Greenblatt actually understates the impact of the book he has written about. I think that the survival and rediscovery of The Way Things Are was a huge event in the development of the modern scientific worldview, perhaps accelerating by a good century the onset of Enlightenment thinking.
I believe this because I believe that really original thinking is hard. In fact I think it is all but impossible; even the intellects we think of as great rarely come up with more than, say, five original ideas in a lifetime. As for truly radical ideas of great importance, has any person ever had more than one? The ancient Epicurean vision of a material cosmos containing nothing but atoms and void provided early modern scientists and philosophers with a template for a truly different and radical view of nature. People who wanted to question the universe they learned about in school -- godly Aristotelianism, more or less -- had in Lucretius' poem a ready-made escape hatch from the dominant paradigm. The Way Things Are was the favorite book of, among others, Giordano Bruno, Montaigne, and Thomas Jefferson, who owned seven copies in four languages and put the wonderful Epicurean motto "the pursuit of happiness" in our Declaration of Independence. Machiavelli, Rabelais, Hobbes, Francis Bacon,and Pierre Bayle were also great fans. Ask yourself this: why was Galileo an atomist? There was no real scientific evidence for the existence of atoms until the late 1700s, when chemists like Lavoisier and Priestley made their exact studies of combustion and other reactions. Galileo was an atomist because he took his view of a material cosmos governed by impersonal forces from Lucretius. For 250 years The Way Things Are was the main repository of this kind of thinking. I think that the presence of this ancient body of materialist lore -- and The Way Things Are was the only Epicurean book that survived into modern times -- made it much easier for early modern thinkers to conceive such a universe than if they had had to start from scratch.
Greenblatt seems more interested in Lucretius' impact on ethics than his scientific influence, and he makes much of the notion that while medieval people pursued pleasure, they were never willing to defend it in theory. In his view the modern world arrives when serious intellectuals start thumbing their noses at the church and holding up a life of pleasure and the highest possible one. Actually societies devoted to sophisticated pleasures spring up wherever people have too much money and time on their hands, including medieval Europe; surely the courtly love circles of 12th century France are one of the purest examples of the type. (Don't get carried away.) It may also be somewhat arbitrary to pin so much on Lucretius, when the discovery of his book was just one episode in the great recovery of ancient learning that began in the 11th century. Aristotle was in his own way every bit as radical a thinker as Epicurus, especially in his insistence on submitting all claims to the judgment of his own reason. But as it happened his works were spread across Europe during an age when all learning was thoroughly controlled by churchmen, and the theologians were able to integrate Aristotle into Christianity without opposition from skeptics. The dismal style of Aristotle's surviving works also limited his popularity in the Renaissance, an era obsessed with literary beauty. So whatever you wish to argue about how other books might have fulfilled the role that De Rerum Naturae played, it was in fact Lucretius' poem that most stimulated the growing materialism and moral skepticism of modernity.
As to why Lucretius had this immense impact, let me offer this suggestion: maybe he was right. The Jesuits who eventually got The Way Things Are placed on the index of forbidden books thought that atomism was an especially diabolical teaching; among the prayers Ignatius Loyola taught his followers was a daily litany against atomism. I think they were right, too; I think any successful theory of an entirely material, mechanical universe fatally undermines Christianity. In the universe of Lucretius -- and Galileo, and Hobbes, and Thomas Harriot and so on -- miracles are impossible because everything about the universe is governed by implacable laws. A philosophical sort of religion can be maintained in this universe, but not one in which God cares about people and sometimes acts to help them, or one with any possibility of an afterlife. I also think that Epicurus drew the obvious moral lesson from Democritus' atomic universe: if God doesn't care and there is no judgment or afterlife, why not try to lead the most pleasant life you can? I think that Epicurus had a very narrow view of the good life -- conversation in pleasant surroundings, more or less -- but without traditional religion it is hard for me to see what we can aim for beyond the pursuit of happiness. And, you know, the universe is made of atoms; maybe that was a lucky guess, but it was certainly an inspired one.
So if you are curious about the origins of modernity and can laugh at a Middle Ages full of ignorant peasants and self-flagellating monks, by all means read The Swerve. It is entertaining, full of diverting anecdotes and well-chosen quotations, and raised in my mind all sorts of fascinating questions about the past and the present.