Saturday, December 15, 2018

Zeus and Aristotle: Explanations of Lightning

A while back I was reading some comments on a blog and someone threw out a statement that made me stop and think for a moment, but definitely not in the way the commenter intended. I wasn't particularly interested in the conversation due to the contentious nature and general lack of epistemic humility, but for some reason his comment interrupted my skimming and made me ask, "Wait, how do you know that?" The statement in question was taken as plainly obvious by everyone involved that even in a contentious online debate no one called him on it and questioned his characterization of historical thought.

It was something so taken for granted that if I tried to question his assertion I would instantly be denounced as ignorant, petty, and "changing the subject" even though his underlying assumption was central to his whole argument, so I chose not to say anything.

As this particular commenter was launching into an elaborate explanation of why his views were right and everyone else's were wrong he stated, "When ancient Greeks 'explained' lightning as coming from Zeus, they were wrong." It was this comment that made me stop and think, "Yeah, but how do you know that is how Greeks explained lightning?"

In context he was using that statement to establish a line of reasoning that went something like this:
  • People in the past were ignorant and believed in mystical, religious explanations of natural phenomena.
  • As science advanced we had less ignorant explanations of natural phenomena.
  • We are enlightened now with our scientific explanations of natural phenomena so we can ignore all the mystical mumbo jumbo of religion.
For him there was an obvious progression from ignorance to enlightenment and the beliefs of the Greeks formed the first data point. But the problem was, how did he know that his first data point was correct?

To put it another way, his argument rests on the idea that people in the past were incapable of making rational, well thought out, scientific arguments, and that now through the redemptive, mystical power of science mankind has been transformed into a blessed state of rationalism.

But all that depends on his first data point being correct.

So how does he know that the Greeks relied on mystical explanations of natural phenomena? On a similar note, how do we know that people today don't rely on mystical explanations for lightning? If you ask the average person on the street today what causes lightning would their answer typically be any more or less educated than the average person's understanding in ancient Greece? What about the average college educated, or the ancient Greek equivalent, person's answer?

So how would an educated Greek respond to the question of what causes lightning? Fortunately we can actually have an answer to that because we have some of the standard science texts from ancient Greece! In a 1965 article by H. Howard Frisinger in the Bulletin of the American Meteorological Society entitled “Early Theories on the Cause of Thunder and Lightning” Dr. Frisinger briefly the different theories of how lightning worked that were taught by various Greek philosophers.

All of the views of how lightning worked were based on the standard Greek physics of the four elements, earth, water, air, and fire. The theories taught by the Greeks, and the answer that your average educated Greek would give, generally attributed movements of air to be the cause of thunder (just like we teach today), and the motion or effects of fire (sometimes aether) as it interacted with the water and air in the clouds. There was debate about what came first the thunder or the lightning, and there was debate about whether or not one caused the other or if they were entirely separate phenomena.

The most widely accepted theory came from Aristotle who wrote that both thunder and lightning are a result of motions of air colliding with objects, such as clouds or other masses of air. If there was sufficient fire in the clouds then a lightning bolt would be formed, and depending on the purity of the fire you either get a defined bolt or a diffuse flash of light in the cloud. He made his arguments by looking at the evidence, such as when a local temple was struck by lightning, or how lightning was know to burn some kinds of materials but leave others unblackened.

These theories were put into the standard science textbooks of the day and would have been expected reading for an educated Greek. Just like today there would have been people who had no idea what the standard "scientific" explanation of lightning was. Then there would be people who were exposed to people who were educated and they might hear the explanation or ask for it. Then there would be educated people who had read extensively, but maybe not books on the weather. Then there would be people who had studied those things specifically and would be considered very knowledgeable on the subject, with a very select few who would be called experts and authorities. Just like it is today.

But all these ancient theories relied on the idea of the four elements! Where our ideas today do not! Surely that proves the point that we have progressed from ignorance to enlightenment!

On the contrary, it shows that ancient Greeks did not rely on mystical, religious explanations of natural phenomena to the extent that people like the commenter think they did. The educated Greek would not likely appeal to Zeus as an explanation for the cause of lightning. They gave natural explanations. These theories, books, and explanations were considered standard and authoritative up until the 1700's when new technologies made it possible to explore electricity and lightning through direct measurements.

Before that people did what they have always done, they gave rational explanations based on their understanding of the universe. In many conversations, and from students that I teach, and even from some of my professors I have seen expressed the idea that as a whole we have progressed from non-rational thought to more modern, enlightened, and rational way of thinking. Certainly our understanding of the universe has drastically changed, but when I read historical materials I find no evidence that that has happened.

There has not been the assumed progression from less rational to more rational thought as is commonly asserted by those who promote science and eschew religion. The evidence does not support that theory.

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