The Cartoon History of Humanism, Episode 2 Lucretius, the MacGyver of Natural Philosophy

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Lucretius, the MacGyver of Natural Philosophy

Lucretius is the keystone of materialism, its prime example of how staggeringly far a single mind can go in understanding the universe aided by nothing but the proposition that everything is composed of atoms. His masterpiece, De Rerum Natura, published over two thousand years ago, is an astonishing encapsulation of prescient hyper-modern insights into the physical world. From genetics to cosmology, optics to neuroscience, Lucretius’s ideas are correct freakishly often, explainable only under the hypothesis that (1) Lucretius was a Time Lord, or (2) a little bit of materialism unencumbered by the need for theogonic consistency goes a long way indeed.

We know shockingly little about the man whose book was, for a millennium and a half, deemed too dangerous for general consumption. We know that, like his role model and inspiration, Epicurus, he lived in a time of tectonic civilizational change. Born 100 BCE-ish, Lucretius experienced the last days of the Roman Republic and died around 55 BCE. During that time, two Roman generals, Marius and Sulla, broke the back of the Republic with their constant wrangling for power, each establishing in turn a rule more tyrannical than the last. Political enemies were executed in droves on the streets of Rome as the vaunted traditions of Roman religion and justice stood impotently by.

Little wonder, then, that a return to the even-handed realism of Epicurus proved so popular. In a world so markedly capricious, maintaining a belief in the rule of benevolent gods was not merely foolish, but harmful. Lucretius, before he gets down to the business of explaining “Life,” “The Universe,” and “Everything,” makes it his first priority to clear away the inherited religious detritus of the Greek and Roman systems, and to remind us of the violence to which religious belief incites men:  “Remember how at Aulis the altar of the Virgin Goddess was foully stained with the blood of Iphigenia… struck dumb with terror, she sank on her knees to the ground… It was her fate in the very hour of marriage to fall a sinless victim to a sinful rite, slaughtered to her greater grief by a father’s hand, so that a fleet might sail under happy auspices. Such are the heights of wickedness to which men are driven by religion.”

He then sits back, proposes the idea that everything we know is the result of entirely natural processes driven by the combination and recombination of elemental atoms, and treats us to a Neil deGrasse Tyson-worthy tour through the resultant recesses of the cosmos and the minds of men. The book is an accomplishment which has only grown more staggering with the passing of time, as ideas that were scoffed away as unworthy in the eighteenth century have since gained vindication from an age able to physically probe the regions he touched with his powerful sense of imaginative rigor. Here is a modest sampling of what he was able to conclude from the vantage point of basic atomism:

  1. The sun is the result of the chance combining of atoms over time, arising out of a natural accumulation, and having an inevitable and fixed end. It is not a deity, not even eternal, but just another natural object that must be constantly diminishing from radiation. The earth, also, is a natural object, with a definite and irrevocable end.
  2. There is a special material substance passed on to children which has within it contributions not only from the mother and father, but from previous relatives as well, the resultant child being determined by the particular ancestral mixture passed on from each parent. So, inheritance is determined by a random remixing of traits from multiple generations encoded on some physical medium… basically, meiotic crossing over and DNA.
  3. New organs and physical variations arise and are kept based on their usefulness. We weren’t created with eyes for the express purpose of seeing, but rather, an eye-like thing occurring throughout the random combinations of living forms, it created the possibility of sight, which was useful. It’s tantalizingly on the verge of our notion of genetic mutation as the motivator of evolutionary change, and a rebuttal of intelligent design two-thousand years before the fact.
  4. The speed of light must be slower in more dense media due to interference effects, and opacity is the result of coherent images being scattered by a non-uniform surface.  Mirror images are the results of reflecting particles, and how far “into” the mirror they appear is determined by an act of physical/mental calculation. Granted, Lucretius thinks the act of computation is triggered by the amount of air a traveling image particle pushes in front of it, rather than the straight-line computation model we’ve since discovered but still, a lot of the basic structures are there.
  5. Air is a fluid, and must be treated as such in all questions of falling bodies. Different objects fall at different rates because of the impact of air particles on the falling body, but in a vacuum, all objects should fall at the same rate, regardless of weight. That’s Galileo.
  6. Sensory motions and reactions are triggered by incredibly small particles which create a cascading chain reaction amongst larger masses of atoms to produce sensation. Lacking our vocabulary of nerves and nerve-triggering neurotransmitters, Lucretius nevertheless once again picked up on some of the salient physical details of sensation—that a miniscule initial physical reaction to a stimulus has to be appropriately amplified through intermediary circuitry, and that somewhere in the automatic processing of that signal lies our sensation of that stimulus.
  7. “It is in the highest degree unlikely that this earth and sky is the only one to have been created and that all those particles of matter outside are accomplishing nothing. This follows from the fact that our world has been made by nature through spontaneous and casual collision and the multifarious, accidental, random and purposeless congregation and coalescence of atoms whose suddenly formed combinations could serve on each occasion as the starting point of substantial fabrics—earth and sea and sky and the races of living creatures. On every ground, therefore, you must admit that there exists elsewhere other congeries of matter similar to this one which the ether clasps in ardent embrace.” Boom.

Sure, there are parts of De Rerum Natura which are just plain wrong. Though he annihilates with devastating cleverness the ancient idea that the whole universe must be made of one of the four classical substances (fire, for example, if you believe Heraclitus), those substances still figure prominently in a number of his explanations. But even some of his seeming absurdities, like the rooster-shaped eyeball pores in today’s comic, hold at their core something very powerful and true. What he was giving utterance to is the idea that we now recognize as true: that molecular shape has a crucial role in how that molecule functions. Bend a protein one way, and it does one job, bend it another, and it does something completely different. Lucretius’s obsession with hypothesizing about the role that atom shape plays, which struck later chemists as comical, was actually a good deal closer to the mark than most chemistry before the mid-twentieth century was capable of realizing.

Our sniggering was premature, as sniggering often is.

Of course, the grand tragedy is that this shimmering moment of potential was produced on the doorstep of Christian cosmological hegemony. If one mind, starting from materialist principles, was able to produce all of those astonishing insights within the span of forty-five short years, what might a whole continent have accomplished in the millennium-and-a-half it took us to allow ourselves the pleasure of his philosophical company again?

Such is the standard lament, but remember that the Greeks and Romans were not experimental people. They were astounding in their ability to take a premise to its logical conclusions, and where the initial premise was good, as it was with Lucretius, the end results were brilliant. But the scientific method of devising test conditions to verify hypotheses is a necessary thing to regular and reliable progress, and who’s to say that the daft fumbling of medieval Aristotelianism wasn’t exactly the thing that we needed to shock us into such a radically rigorous way of searching for knowledge? Perhaps the poetry of Lucretius was too alluring an intellectual diet to spark such a fundamental departure in scientific thought.

Ultimately, Lucretius stands at the zenith of ancient materialism, and the traditional story goes that our humanist thread doesn’t get picked up again until perhaps the fifteenth century. But, as Mikhail Bulgakov noted in a different time of darkness, “manuscripts don’t burn,” and our next few figures represent startling returns to the best classical traditions during the most unpromising of times. So join us in three brief weeks as the Cartoon History of Humanism marches boldly into the heart of the Dark Ages!