This is a story about Democritus, Epicurus, Lucretius and Pierre Gassendi and some unpopular ideas. Who are these guys and why should you care? Good question so let's dig in. You'll have to forgive me but I'm going to mention a few dates. The dates are significant because they allow you to see how these fellows relate to each other and who might have influenced whom, or not.

Epicurus
Let's begin with Epicurus who lived from 341 BC to 270 BC. That makes him a little more recent than Aristotle (384-322 BC) with a slight overlap. The reason that is significant is that Epicurus believed just about everything Aristotle did not. To begin with, he favored the atomic theory of the universe developed by Democritus (460-370 BC) who himself preceded Aristotle by a few years.

Democritus
Democritus developed the atomic idea although he gave the credit to someone he called Leucippus whose existence is in fact doubted by some. According to him, all things are composed of minute, invisible, indestructible particles of pure matter. Sounds familiar doesn't it? Keep in mind that this is more than two thousand years ago. To Democritus the "creation" of worlds was the natural consequence of the ceaseless whirling motion of atoms in space.

This has a distinctive evolutionary flavor which was one of the reasons Aristotle did not approve. You see Aristotle's universe had a heavenly sphere with likely a divine origin and propelled by a Primum Mobile or Prime Mover, a self-moved force that drives all motion. To the medieval church this was God so you can see that the church wouldn't be too impressed with Democritus either.

But wait, it gets better. Democritus also wrote on ethics, proposing happiness, or "cheerfulness," as the highest good, a condition one could achieve through moderation, tranquillity, and most important, freedom from fear, leading some historians to call him the laughing philosopher. This too would be a little difficult to square with the church's quest for salvation in the hereafter by depriving one's self in the here-and-now.

It's useful to know where Democritus was coming from because that's where Epicurus got a lot of his inspiration and he is of course the next one in our group. If you think Democritus' ideas got short shrift from the medieval church you won't be surprised to hear that those of Epicurus were loved even less. Incidentally, Epicurus and Epicureanism had nothing to do with good food or even a hedonistic lifestyle.

Epicureans did believe in having a good time but not the way you think. The essential doctrine of Epicureanism is that pleasure is the supreme good and main goal of life, but they meant intellectual pleasures. Sensual pleasures tend to disturb rather than enhance peace of mind. True happiness, Epicurus taught, is the serenity resulting from the conquest of fear of the gods, of death, and of the afterlife.

The ultimate aim of all Epicurean speculation about nature is to rid people of such fears. You can imagine the average medieval church father choking on his sacramental wine! Then there were his ideas in biology. Here he anticipated the modern doctrine of natural selection. He suggested that natural forces give rise to organisms of different types and that only the types able to support and propagate themselves have survived. Can you say survival of the fittest?

No, when it came to ancient Greek wisdom there were, in the eyes of the Church, good guys and bad guys and Epicurus would not be one of the good guys. Even in the ancient world there were those who did their best to discredit him and his followers by accusing them of impiety. Epicurus' quest for happiness by abolishing fear was cleverly turned into a lusting after hedonistic pleasures which is why even today we associate epicureanism with La Dolce Vita, the "sweet" life.

Nevertheless, he enjoyed a large following in the ancient world where his ideas were actively endorsed and preserved by both Greek and Roman philosophers. In fact the Epicurean philosophy prevailed until the beginning of the fourth century AD which is coincidentally when Christianity became the state religion of the Roman Empire.

Lucretius
Much of what we know about the Epicurean philosophic view comes to us via the work of the Roman poet, Lucretius. This is why he is next on our list. The poem De Rerum Natura (On the Nature of Things) by Lucretius is our main source of knowledge about Epicureanism.

His full name was Titus Lucretius Carus. He lived from approximately 98 BC to 55 BC and like Epicurus, whose ideas he championed, he sought to free humanity from the fear of death and of the gods, which he considered the main cause of human unhappiness.

The Epicurian themes are all there: the universe as aggregations of atoms moving in the void, purely natural causes for earthly phenomena, and the idea that the soul is not a distinct, immaterial entity but a chance combination of atoms that does not survive the body—all beliefs designed to prove that the world is not directed by a divine power.

According to Lucretius, fear of the supernatural is without reasonable foundation. He doesn't deny the existence of gods, but he thinks of them as having no concern with the affairs or destiny of mortal man. It strikes me as interesting that much of the early resistance to these ideas came from what we would call the pagan cultures of Greece and Rome. I'm guessing they had much the same objections as the Church did later on.

You see, contrary to popular Christian opinion, much of what we think of as Judeo-Christian teachings appear to have their roots elsewhere much of it Greek philosophy. This is why Epicurean thoughts met with hostility long before Christians became aware of them. That the medieval Church was opposed to the Epicurean philosophy goes without saying.

Pierre Gassendi
This makes the next person on our list such an unlikely hero of our story. His name was Pierre Gassendi and in spite of his Italian sounding name he was a French philosopher and man of the cloth. He was born in Champtercier, near Digne in 1592 and was educated both there and the universities of Aix-en-Provence and Avignon.

He served for a time as professor of philosophy at the University of Aix-en-Provence. In addition he traveled to Flanders and Holland working on studies in science and philosophy. In 1634 he was appointed chief administrative officer of the cathedral at Digne. In 1648 he retired as professor of mathematics at the Collège Royal in Paris.

No one knows for certain why Gassendi, a devout member of the Catholic Church, became enamored of the Epicurean philosophy but he is credited with its rediscovery. In 1647 his De vita et Moribus Epicuri (On the Life and Character of Epicurus) was published, followed two years later by two more works on the ancient Greek philosopher.

It is known that he wasn't overly happy with Aristotle's take on how the world works which had been the mainstay of Church dogma for nearly five hundred years. This also meant he was opposed to the teachings of Thomas Aquinas and the rest of the Scholastic movement. Epicureanism with its atomic theory of matter was a taylor-made alternative. Even so some of the other Epicurean notions concerning God may have created some difficulties.

He did advocate a way of bringing Christianity into line with atomist thinking even though this tended to deprive the Christian God of some of his traditional roles. The Scholastics had taught that Aristotle's Prime Mover had not only assembled but also continued to sustain the world as we know it. And so the God-fearing Pierre Gassendi single-handedly began a new world order in which "creation" became more the product of eternal laws instead of an eternal creator.

Neither Copernicus nor Galileo had fully rid themselves of the Aristotelean idea that heavenly motion, being perfect was circular. That is why their Sun-centered universe still had all the orbits go around in perfect circles. In fact his attachment to purely circular motion actually led Galileo to reject Johannes Kepler's subsequent theory of elliptical orbits.

What was needed was a way to explain Kepler's discovery of how the orbits really worked. Two of Aristotle's dearly held beliefs had to be challenged namely that the natural motion of the heavens was circular and that without a constant push, bodies would stop instantly. What was needed was the concept of inertia. Once again, Gassendi to the rescue. He may not have thought of it first but he certainly actively promoted the idea.

As Newton later showed, if you apply gravity to what is true natural motion namely the tendency for a moving body to continue in a straight line, you tend to get an elliptical orbit. Isaac Newton is quoted as saying that his breakthroughs occurred because he stood on the "shoulders of giants." He'd be the first to include Gassendi's "shoulders" among them. Now you know about him too.

So what do we do with all this stuff. Well, let's see. Since about 500 BC, Western man has been aware of two distinct world views—two ways of explaining how the universe worked. One depended on divine intervention at every turn the other did not. To be sure, the ideas were far from complete and initially there were many gaps but the main thrust was there.

The better known of the two was promoted by the likes of Aristotle, the neo-Platonists, Saint Augustine and the Scholastics. It held that the earth was the center of the universe and that the whole arrangement was likely created by an omnipotent God who continued to make things work by on-going intervention. The nature of that God may have altered over time but the being remained.

The reason this gained greater acceptance is because it was promoted by the entire Christian church and before that, the Greek and Roman mainstream was inclined to give the credit to their pantheon of gods. That made the other theory, which we would now call the mechanistic view, a pretty tough sell. Nevertheless, as we've seen there were quite a few people that supported this alternative view.

Not only was Democritus' atomic theory of matter well developed, Aristarchus of Sámos who lived in the third century BC, had already come up with the idea that the earth revolves around the sun. In fact he even developed a pretty good method for estimating the relative distances of the sun and moon from the earth.

I guess that's what we can take away from this story. It is not the case that man had to accept the traditional view of a God-directed, earth-centered world because he didn't know any better. There was an alternative which he chose to ignore. As we now know with hindsight, it was closer to the truth.

One can only wonder if today there are other ideas that are still getting short shrift because they are unpopular or unacceptable to the mainstream. Food for thought!

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