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History of Philosophy Without Any Gaps
HoP 482 Indivisible, Under God: the Revival of Atomism
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Hi, I'm Peter Adamson, and you're listening to the History of Philosophy podcast, brought to you with the support of the Philosophy Department at King's College London and the LMU in Munich. Online@historyoffphilosophy.net Today's episode Indivisible under the Revival of Atomism One thing you need to learn as a baby is that physical objects don't just vanish into thin air. And one thing you need to learn when you get older is that sometimes they do. I don't just mean the magician's assistant who vanishes after stepping into a box on a stage. A young child might observe a puddle on her way to kindergarten and then notice that it's gone. When she's heading home at lunchtime, affronted by this violation of the entirely reasonable laws that have otherwise been governing the universe, she might ask her mother where the puddle has gone. Oh, the mother will say, it evaporated. Only much later will the child understand what this means. Once she finally reads Aristotle on weather phenomena, he explains that water on the surface of the earth transforms into moist exhalations, which then condense into cloud. Saturated clouds in turn produce rain, which is where we get the puddles in the first place. So mom knew what she was talking about. Aristotle's exhalation is really just the same as the vapor contained within the word evaporation. Plausible though this sounds, our former kindergarten child may press for more information, asking how and why the water in the puddle just changes itself into vapor without a single magician in sight. Aristotle and his followers would say that it is because the four elements mutually transform one another. Small bits of earth might dissolve in a large quantity of water and indeed turn into water, their dryness overcome by the wetness of the water. Similarly, the water in the puddle is exposed to air, with the result that its cold and wet nature changes into the hot and wet nature of air. The process will obviously be accelerated by additional heat, for instance, from the sun, which is why puddles evaporate faster in summer than in spring. Again, this sounds quite plausible, but in the background some pretty big assumptions are being made. The Aristotelian elemental theory assumes that earth, water, air, and fire have their qualitative features hot and cold, wet and dry because of their substantial forms. When one element turns into another, featureless prime matter survives through the change, and there is a swapping of forms, with the form of air replacing that of water when it evaporates. We can perhaps think of the moist vapor as a kind of middle state or mixture between Pure water and pure air. Alternatively, we might think that this whole story is nonsense and that there is no such thing as prime matter or substantial forms. In the early 17th century, an increasing number of philosophers and scientists were reaching exactly that conclusion. Descartes is famous for his rejection of substantial forms, but he was only part of a wider movement that challenged Aristotelian orthodoxy. Another critic was Sebastian Basso, whose book Natural Philosophy Against Aristotle was published in Geneva in 1621 and was known to Descartes. The skeptic Le Verier deemed it one of the hundred books that should be found in any well stocked library, and you can see why it appealed to him. Basso mounts a relentless attack on Aristotelian science, and unlike Gossandi, in his somewhat more polite critique from around the same time, he's perfectly happy to condemn Aristotle himself. With his nonsensical and inconsistent ideas about substantial forms and confusions about such basic phenomena as mixture, Aristotle has, in Basso's opinion, greatly set back the cause of the natural sciences, especially medicine. The few good ideas to be found in his works are all stolen from more insightful predecessors, whom Aristotle then had the temerity to criticize. All of this is fairly familiar from the polemics of Renaissance humanists. What distinguishes Basso is the system he suggests as a substitute for Aristotle's. His alternative physics postulates microscopically small atoms, explicitly taking inspiration from the ancient theories of Democritus and Plato. Like Plato's Dialogue the Timaeus, Basso's treatise has the four familiar elements being made up of differently shaped particles, whose geometrical properties determine the causal and sensible properties of air, earth, fire and water. For example, fire atoms have sharp angles, which is why fire destroys things so readily. Basso uses his theory to explain everyday physical events, including evaporation. When the sun shines on a puddle, the fiery particles that make up the sunlight enter into the water. Water atoms then cluster around these bits of fire, and the vapor that rises from the puddle consists of the resulting corpuscles, each droplet of vapor being a tiny little spark of fire encased in a watery sheath. These droplets rise into the atmosphere until the pressure exerted by the water atoms squeezes the fire back out, at which point the water falls back to the earth as rain. If you had told me this story when I was seven, I think I would have found it perfectly satisfying. And such accounts were pretty popular in the 17th century, too. Anti Aristotelian theories of matter were being put forth around this time, not just by Basso, but also Descartes early inspiration, Beckmann and others besides, such as Daniel Senart and David Gorlajos. I discussed these last two back in episode 389, which was devoted to theories of matter around the turn of the 17th century. Of course, disagreement with Aristotle didn't mean that all these authors agreed with each other. For one thing, there's the fundamental contrast between corpuscularianism and atomism. A theory like Descartes would take corpuscles, or tiny bodies, to be fundamental, while denying that there are atoms instead. All bodies are nothing but extension, and every extension is always, in principle, divisible. Basso's fundamental particles are instead genuinely atomic, meaning that they are indivisible. But his physics lacks some of the features we would normally associate with atomism. He denies the possibility of void, for one thing, and for another, he still accepts the four familiar elements. As we just saw, he thinks that the universe has an unmoving mass of earth at the center, followed by water, then air, fire and the heavens. So for all his anti Aristotelianism, one might say that Basso's world is superficially a lot like Aristotle's. It's just that at a more basic level of analysis, everything is happening because of atoms and their interaction. In this respect, his theory is very similar to that of Abu Bakr Arazi, a doctor and philosopher from medieval Persia. You can go back to episode 126 for him, or read the book I wrote about him. This may be no coincidence, because both Arazi and Basso seem to have based their atomism, especially on Plato's Timaeus. That would in turn help to explain why Basso's atomism is so different than that of Pierre Gassandi. As we saw last time, Gassandi was reviving epicureanism, not the physical theories of Plato. Thus he was a strong proponent of void or empty space. Not just the theoretical possibility, but the reality that there is void all around us, interspersed with the atoms. His most important reason for this belief was taken straight from Epicurus. If there were no void, then space would be completely full and motion would be impossible. Basso would disagree. Alongside the four usual elements, he postulates a fifth kind of body called aether, which pervades the universe and surrounds the atomic particles of fire, air, earth and water, leaving no empty space or gaps around the atoms. Basso also thinks that these elemental atoms are being moved around by the motion of the ether. The particles of the other four elements are inert and passive, just sloshing around and being combined and separated by the Aether. An obvious question here would be, why then is the aether moving? Basso offers the usual explanation of last resort in philosophy of this period. It's God who is moving the ether, indeed moving it constantly. Both the continued existence of all bodies and the motion of the ether which is passed on to the other atoms, are directly caused by God at every moment of time. Again, this gives us a contrast to Gosandi. He also appeals to divine action in his physics, but only to explain the initial motion that has been granted to every atom at the moment of its creation. Ever since the universe was first created, the atoms have been moving through the void with that same initial motion. And the diversity of bodies we observe results from their combination, for example, because atoms, whose shape includes tiny hooks get entangled with one another. This is no random process, as the ancient Epicureans had taught, but is guided by divine providence. Gosanti compares the production of our complex visible world out of its invisible atomic components to the way letters can come together to form words and sentences. He might have extended the metaphor to say that God is therefore like an author writing the book that is the Universe. But where Basso thought that God is busily composing the world from moment to moment, much as the occasionalists would say, Gosandi is strongly in favor of secondary causation. In other words, he thinks that God sets up the universe by laying down physical laws and giving the atoms their initial motion. But after that, the atoms are perfectly capable of coming together and producing all the results we study in science. Atoms and larger bodies are not only occasional causes, they are real causes. Gosanti does have something else in common with Basau, though. Both of them want to explain all natural phenomena in terms of the motion and interaction of atoms. Gassandi, too, thinks that liquid turns to vapor because of the dispersal of atoms. Sunlight speeds up this process because light is made out of particles that convey heat. We see because our eyes are affected by those same light particles. And here, because of vibrations in the atoms and the air, magnetism and gravity are explained in terms of atomic chains that bind and pull bodies towards one another. Unlike Basso, Gosandi also has void available as an explanatory principle. It accounts for differences in density, as we might expect, but also the ability of light to pass through apparently solid glass. Space in its own right, is boundless, and God created the universe within it. So our visible universe is, as Antonia Lolordo says in her fundamental study of a finite island in an infinite sea of empty space and time. This, too sounds very Epicurean and not at all Aristotelian. In yet another difference from basso, Ghassandi rejects geocentrism. Actually, he can't accept centrism of any kind, since space is infinite and has no center. But what I mean is that he. He doesn't think the heavens are rotating around the Earth. He's careful not to endorse Copernicanism openly in the way of the condemnation of Galileo, and allows that Tycho Brahe's system might be a good compromise. But a treatise he wrote on motion is pretty clearly intended to clear the way for Copernicus. It carefully explains that often things that seem to rise or fall in straight lines are in fact moving along a curve. He gives the nice example of tossing something upwards while on a galloping horse. If you do it perfectly, the object will fall right back into your hand, even though you will have traveled a considerable distance forward. In 16:40, off the coast of Marseille, Gossandi also tested out the much discussed case of dropping something from the mast of a moving ship and satisfied himself that the object will fall right to the base of the mast. The point of all this is, of course, that projectiles are moved along with their frame of reference, as we might put it today, which explains why stones seem to fall straight down even though the Earth is moving. But as I say, Gosandi doesn't spell that out. What he does say explicitly is that an object in motion will always continue along its path unless it is somehow obstructed, for example, by a dense medium that slows it down. If we imagine an object thrown in infinite void space, we must conclude that it would just keep going forever. Likewise for a perfect sphere rolling on an endless, frictionless surface. Presumably, this is why atoms just keep going. Once God creates them with their initial motion, they can collide and change direction, but they never stop or slow down. Thus, visible bodies that are not moving must, at the microscopic level, be a vibrating mass of constantly restless particles. That's one example of a more general and rather problematic feature of Gossandi's physics. Though the behavior of macroscopic bodies is meant to be explained in terms of atomic motion, there are a lot of differences between the micro level and the macro level. Macroscopic bodies can come to rest or slow each other down. Atoms, by contrast, apparently move at the same speed forever and can only be made to change direction. And that's only the beginning. Macroscopic bodies have color, can be smelled, can transform into one another, can have children. And when they are children, they can go to kindergarten. Adams can't do any of these things, though in my kindergarten there was one Adam son, actually two, because my brother was there also. And our teacher would have agreed with Gosandi that we were restless, vibrating masses of particles. How then can Gosandi bridge the gap between the atomic and everyday worlds? Well, like Descartes with his theory of extension, he can't. But he's going to give it a good try. Kasandi's main strategy is to postulate a level of reality that mediates between atoms and macroscopic bodies. Often he speaks of the textures formed by atoms that have gotten tangled together, much as a cashmere sweater feels smoother than one made of wool because of the differences between the fibers. So different bodies will differ in colors and other properties thanks to these textures. To explain more sophisticated physical processes, Ghassandi resorts to a further explanation, so called seeds that are found in many bodies. This is another idea with ancient roots, in this case especially in the Stoics. But Ghassandi thought the seed hypothesis could also be supported empirically. He was impressed by the development of crystals, something he studied together with his friend Pierrek. This is a relatively rudimentary case of something Gossandi takes to be a pervasive phenomenon, where structures at the level of corpuscles are replicated through a process of growth, giving rise to larger versions of the same structure. We can observe it in plants, noting that the whole plant already seems to be present in the bud, all folded up and ready to expand as it takes in nourishment. From such cases, we can infer that within the invisibly small confines of seeds, something similar is going on. Even in human reproduction. The male and female seeds should contain structures that will express themselves within the developing embryo. Gosandhi goes so far as to say that there are miniature souls in the seeds which steer the distribution of matter within a developing organism. Gosandhi makes no real effort to spell out how such complex designs could emerge out of something so simple as atomic interaction. If pushed, he would presumably just say that God has set up the world so so that such higher level structures will in fact emerge from atoms. While that may seem unsatisfying, Kasandi is convinced that his account is at least better than anything Descartes has proposed. His own atoms have a divinely instilled motion that they never lose, whereas Cartesian bodies are nothing but extension, so that it's hard to see how they could ever do anything active as opposed to just occupying space. Active as they are, Gossandian atoms can supposedly explain even the vital functions of plants, animals and humans. These are carried out by souls. But these souls are like all other bodies, just complex aggregates of microscopic particles. So for Gassandi, no less than for Descartes, biological processes are really mechanical processes. On the other hand, Gassandi also agrees with Descartes that humans are more than living machines. In addition to a vital or animal soul, which is material and made up of atoms, each of us has an incorporeal immortal soul. Early in his career, Gosandi postulates a separate soul purely on the basis of his Christian faith. But later on he comes to think of it as a doctrine that can be proven rationally too. Nonetheless, this seems to be one of those areas in Gosandi's thought where Christianity serves to correct the dangerous implications of Epicurean philosophy. Just as he rejects the Epicurean conception of a random and eternal universe, instead of holding a created universe ruled by divine providence, so he distances himself from Epicurean materialism. Human, rational souls, as well as angels and of course God are the exceptions to his ambition to explain everything in terms of atoms and void. Like his epistemology, which checks the overweening ambition of humans to know everything with certainty, Gosandy's physics is carefully harmonized with his Christian faith. And he wasn't alone in this. Atomism might seem dangerous from a religious point of view because it could so easily lead to materialism, but in fact, atomism seems to have appealed to many thinkers around this time precisely because it fits so well with their religious convictions. In Gosandi's case, the underlying rationale would be that a world of atoms can be fashioned into whatever God chooses. There are no substantial forms or essences to worry about, just atoms of various shapes, the letters with which God can write whatever story he likes. As a Catholic priest, Gosanti might well have been appalled at the enthusiasm for atomism among Protestants. A big advantage for them was that atomism seemed to rule out the Catholic theory of the Eucharist. If sensible properties are just the result of atomic structure, then it makes no sense to suppose that the sensible features of bread and wine seems still belong to substances that are no longer bread and wine because they have been miraculously transformed into the body and blood of Christ. This is why we see some admittedly rather obscure 17th century Protestants embracing atomism. Like David Derradon, who not coincidentally followed a treatise on atomic physics in 1661 with several treatises on the Eucharist, Derredon made the connection between theology and physics as as clear as the crystals studied by Perec and Gassandi. Since wetness is a kind of fluidity, it follows that the fluidity and wetness of wine and the firmness and dryness of bread cannot be without the substance of bread and wine, even by divine power. It's a reminder that in the 17th century, scientific and philosophical ideas were often coupled with religious concerns. That's certainly what we'll find with the next couple of figures. We're going to tackle Blaise Pascal and Antoine Arnaud. We've come across Arnaud a few times already, but when we come to treat him in his own right, we'll see that his philosophy was intimately linked with a religious movement called Jansenism. As for Pascal, I'll wager that a lot of you can think of an argument he devised in favor of religious belief. But don't place your bets just yet, because before we get to Pascal's wager, his famous argument for believing, or maybe trying to believe in God, we need to introduce the man himself. So join me next time for a true trailblazer. Blaise Pascal here on the history of philosophy, without any gaps.