Book Cover for Reading Lucretius in the Renaissance
(Harvard University Press)

The work of the the Roman writer Lucretius was lost to the world for more than a thousand years. When his poem “De Rerum Natura” was rediscovered in the Renaissance, Lucretius’s ideas slowly started to percolate through Renaissance Europe, making it possible to imagine a world that was not shaped by everyday divine intervention, in which we could begin to study both the universe and the behavior of human beings in their own terms. Niccolo Machiavelli was among the thinkers profoundly shaped by Lucretius’s ideas. Machiavelli’s own arguments about the virtues of republican order and the proper behavior of princes are the ancestors of many of the most crucial ideas of political science today.

Ada Palmer is an assistant professor of history at the University of Chicago, and the author of “Reading Lucretius in the Renaissance,” as well as a science fiction novel, “Too Like the Lightning,” forthcoming from Tor in 2016. I asked her about her research on Lucretius (which uses both different editions of his work, and the annotations and marginalia that readers left in his books to understand how people read Lucretius in the centuries immediately after his work was rediscovered.

HF: Lucretius’s ideas are crucial to the creation of the modern world (even if his world view is starkly different to our modern understanding). However, when his book, “De Rerum Natura” was rediscovered in the Renaissance, he was initially read as one of many classical writers whose rhetorical skill might inspire virtue in princes, and his ideas about atomism were dismissed as errors. How did this change?

AP: There were two big changes that made it happen.  First, the book became easier to access and easier to read.  Before 1480, the poem existed in a few dozen hard-to-read manuscript copies riddled with transcription errors, which made its difficult archaic Latin even harder to read, confining its appeal to skilled Latinists, most of whom cared more about antiquity and literature than radical ideas.  But over the course of the 1500s the Latin was corrected, the book was printed in easy-to-read text, editors added commentaries, glosses and vocabulary guides, and thirty print editions turned a few dozen copies into tens of thousands of copies.

By 1600, all you needed to do to read Lucretius was to go to the nearest decently-sized print shop or private library and pull it off the shelf. Not just philologists and classicists but all kinds of educated people could read it easily, allowing it to enter the discourse in a new way.  The other major change was that new questions developed over the course of the 1600s, as discoveries such as the circulation of the blood, the New World, and magnification — poked more and more holes in the ideas about the world that had been handed down from Aristotle and Ptolemy. This created a generation of radicals and curious people actively looking for new answers since the old ones weren’t working.  Thanks to the efforts of earlier philologists and printers, when they went looking, Lucretius was an easy place to look.

HF: Why were his ideas about the separation of physics from the divine and atomism (the notion that all matter is made up of tiny parts) important and influential?

AP: Lucretius wasn’t an atheist, but he provided our oldest coherent explanation of how the universe could function without divine intervention to make it go, telling us how tides and clouds and lightning could work on their own without gods like Zeus and Helios to make them work in a hands-on way.  So, even though Lucretius himself thought that gods existed, his system was the first one where you COULD have atheism, you could have a coherent science, and even a coherent moral philosophy, if you took the gods out of the equation.

In the Middle Ages, before the rediscovery of Lucretius, someone who wanted to make an argument for atheism would also have to scrap all established science and moral philosophy. If they were asked “How does the Moon move?” or “Where did the world come from?” or “How do you differentiate good and bad choices?” they would really have to say, “I have no idea.”  It’s hard to turn your back on all the established answers and move forward with nothing.

Lucretius showed that it was possible to have a coherent model of the cosmos and of ethics without divine participation. Even if radicals from the 1400s through the 1700s weren’t actually persuaded that Lucretius’ Epicurean system was true, they could look at it and say, “Hey, look, it’s possible to create a science and an ethics without God involved at all, and if Lucretius can come up with one maybe I can come up with another, better one.”  It proved that atheism could be a system, instead of just a single isolated thesis that required the adherent to scrap all other knowledge.

HF: What do marginalia – the comments that people wrote in the margins of different editions of Lucretius’s poetry – reveal about how contemporary readers read his poetry in the centuries after it was rediscovered?

AP: The “De Rerum Natura” is a very long book with many sections treating topics from poetic descriptions of nymphs and satyrs, through symptoms of disease, weather, magnets and astronomy, to a sex scene and recommendations of sexual positions conducive to pleasure and fertility.  When readers read, they made more or fewer markings in different places. This means that by comparing hundreds of copies it is possible to tell what parts people were most interested in and what kinds of marks they tended to make, and to spot unusual ones.  Only a few sections concentrated in Book II contain what we would call the nitty-gritty details of atomist physics, arguing for the existence of vacuum, how substances are formed, etc.

What I have found is that practically all the early copies had no notes at all there, or very few, far less than most other sections of the text. This suggests that people skimmed or even skipped those parts, concentrating their notes on the parts with elegant language, moral philosophy advice, or the sex scene.  But there are notes concentrating on that section in Machiavelli’s copy and in three other copies belonging to particularly interesting humanists. There are a lot more markings in these sections in copies from the last decades of the 1500s, right before the start of the 17th century, when readers became less interested in classicism and language, and more focused on science.  What this shows is that there were always a few people interested in the atomist sections of the text, but that it went from a tiny percentage around 1500 to the majority by 1600.

HF: One of the most famous readers of Lucretius was Machiavelli, whom you describe as the first social scientist. How did Lucretius influence Machiavelli’s thinking and the social scientific endeavor?

AP: There are many books and speculations about that. I focus on one aspect.  Machiavelli is the founder of Utilitarian ethics, an approach under which one can judge whether action is good or bad based on its real world consequences, what it helps and what it hurts.  Utilitarian ethics operates for the most part as if the world exists by itself, in a vacuum, without any bigger metaphysical things outside it to enter the equation.  That makes it very different from the kinds of ethics that were common in Machiavelli’s day, which usually judged good and bad based on divine laws, or how they affected the soul.

In a sense you can call utilitarianism a kind of “closed system” ethics– if we had a bunch of organisms that lived in a terrarium, Machiavelli’s utilitarianism would involve the organisms deciding what to do based on the needs of the community inside the terrarium, without worrying about the enormous beings outside that sometimes reach in and interfere, or worrying about what might happen if one of the organisms ever left the terrarium (i.e. the fate of the soul after death).  Now, Machiavelli’s new utilitarian ethics is nothing like Lucretius’s ethics, but Lucretius offered Machiavelli a way of thinking in which there are beings outside the terrarium, but the beings never look at it or open the lid, so we don’t need to worry about them.  When Machiavelli read Lucretius, and we know from his annotations that he read the atomist sections with extraordinary–in fact unique–interest, I think he saw Epicurean ethics and was excited by it as an example of how you could create an ethics that operates by itself, inside the terrarium.  That helped Machiavelli then think about how to make his own ethics, which is completely different, but operates in the same way, as a closed-lid system, that doesn’t worry about how any outside divinity might judge things, or about the possibility of leaving the terrarium (i.e. the afterlife).

I also think that Machiavelli was excited by Epicurean science as an alternative to the theologically-based science he was used to, again because it fits well with a closed-lid system.  A lot of people suggest that Machiavelli was an atheist because of this, and that is one way to read it, but it isn’t necessarily the case, since a closed lid terrarium ethics is just as compatible with something like Epicureanism, or Deism, where the Clockmaker set up the world and, in many versions, watches it, and even receives souls after death, but doesn’t ever open the lid and intervene in a hands-on miraculous way.  There are many kinds of radicalism beyond just atheism that you can look for in these early radicals, and that’s one of the reasons it’s so exciting to see the different ways that different people used Lucretius at different points after the text returned.