HON 280 -- LECTURE NINE (Ptolemy to copernicus)
THE DEVELOPMENT OF SCIENCE
I. End of our discussion of Hellenism?
A. Last time, we talked mainly about Ptolemy and how one goes about assessing a scientific theory. Is it always the case that what makes one theory better than another is its empirical adequacy, or does simplicity ever play a trumping role?
B. Medicine begins with Hippocrates and Galen. Both do dissections (on animals and/or people). The distinguished the nervous and circulatory systems.
II. Medieval period: my treatment of the next 1000 years is going to be nothing short of criminal in its briefness.
A. All falls into darkness at least in Europe? The west loses its own heritage, which only gets preserved by the East and the Muslim south.
1. The Nestorians, remember those guys. What did they believe and why did it get them kicked out of Europe? God and Christ have have two distinct essences on their account, and are, in consequence, two different beings? This meant that there were certain things they couldn't say which Roman Catholicism required people to believe, e.g., God was crucified or God died for our sins.
2. So they retreated to Syria and Persia and that's where the remaining Aristotelian texts went, along with others. We'll come back to this.
III. One way of understanding medieval philosophy and natural philosophy is by thinking of it as a pendulum recurrently swinging back and forth between Plato and Aristotle. The major transition that occurred in the middle ages was a transition from Plato to Aristotle, as people try to use each in turn as a resource with which to provide some kind of solid intellectual foundation for Christianity.
1. Now, of the two, which do you think is more easily assimilated to Christianity?
2. Probably Platonism. Think about materialism and the form of the good, take one "o" out of the form of the Good and you have, in large measure, God.
IV. Augustine of Hippo (400 CE) chose Plato?
A. He even addressed the question of why he wasn't just a Platonist and he said because God is better than the form of the good because he can love you back.
B. He's the first guy to fully articulate the theory of history that pervades Christianity, especially fundamentalist accounts.
1. Satan falls due to pride,
2. Then human in the Garden of Eden fall to pride
3. From which we get the original sin thing
4. Then the birth of Christ to take the weight of our sins on his own shoulders (because only an infinite being can rectify a sin committed against an infinite being).
C. As a consequence of this theory of history, Augustine He didn't care all that much for science. He wasn't entirely against it. But he largely thought it was a waste of time, because people should be concerned with saving their souls, not finding out what allows arrows to fly through the air. He thought of the physical world as mere eye candy, like Plato, but for different reasons. Rome was sacked in his lifetime. So, he and many others assumed that the end times were near.
D. However, Augustine did engage in theoretical speculation about nature where such speculation bore on theological issues. So, time for instance. A problem -- what did god do before he created the world. Augustine's solution was to dismiss the question as unintelligible on the grounds that extended time is a construction of the human mind. Explain.
V. Through the latter middle ages, people returned to natural philosophy largely because Aristotle became resurgent, thanks largely to the Muslims.
A. Mohammed (died in 632 CE) was like Alexander. His influence was astounding. Within a hundred years after his death, Islam had expanded enormously
1. In the east: from the Arabian Peninsula through Persia.
2. In the west, it reached as far north as France, until it was stopped by the grandfather of Charlemagne, after which it retreated behind the Pyrenees and settled in Spain to create a wonderfully productive civilization with the greatest amount of religious tolerance to be found anywhere. Muslims, Jews and Christians worked side by side to translate and interpret Aristotle and other Ancient Greek thinkers. This is how Aristotle's works were reintroduced to Europe.
B. People were attracted to Aristotle. The world had not ended in 1000 CE. There was a growing interest in the natural world, perhaps because people decided that judgment day was not just around the corner. But there were problems using Aristotle to supplement the Bible. Aristotle said things like,
1. The universe always existed.
2. A prime mover existed but was not a personal god. She didn't intervene, so no miracles.
3. No immaterial souls (functionalism). Form could not exist independently of matter (and vice versa) Hylomorphism, and anticipation of Functionalism.
C. So, this became the real task: How to reconcile the two? Broader question: reason vs. revelation or reason vs. faith. One philosopher Anselm (approx. 1100 CE) said that faith made reason possible, it opened the mind to the light of truth.
VI. Thomas Aquinas however (1250) gave a different answer, suggesting that there is an overlap between reason and revelation. That is, some claims can be demonstrated either way. Some claims can be proven by one, but not the other. Of course, where there is a conflict, revelation wins.
VII. This subsequently caused all sorts of fireworks. Some folks remained very distrustful of philosophy, especially natural philosophy. They reasoned, maybe philosophy could answer other questions about the natural world, but why bother, if they'd been important, they would have been mentioned in the Bible.
VIII. There were dissenters. Some were open. Others were covert. There proved to be a sneaky way of doing theoretical physics, for instance, in the guise of theology. This stuff is really well described from 36 to 39.
1. For instance, how could one's grace or charity be increased in a person? This led to a more basic question: what is it for something to change, a return to the original motivating concern of the Greek nature philosophers, right? For instance, did change increase in quantum units or on a continuum? What reason was given for thinking that it occurred in quantum units?
(a) Well, if it’s a gift from god, then it is natural to suppose that it is supplied to us in discrete packets?
(b) But others thought this was a restriction on god's power. It's to say that god can increase one's charity by a unit of 1 or 2 or 3, etc, but not by 11/2.
4. This lead to other more general discussions of the nature of change. For one's level of charity to increase requires a modification in their form. But how was this to be understood? How could a new form flow into an object? Is it like changing elevator lights or a moving swing (analogy on p. 37)?
5. Moreover, if you're going to think about change, then you're going to think about motion, which is a particular kind of change (i.e., change in position).
(a) Aristotle had talked about motion as mere change in position.
(b) But medieval wondered if that was all. Does it increase by intensity? This led them to add speed to direction to bet the notion of velocity.
(c) A further observation made by Oxford scholars was probably the first quantitative principle of motion in history: If you have an accelerating body, it will cover the same distance as that body traveling at the average motion over the same period of time. Nicole Oresme (1350) then proved it, applying graphic techniques to the analysis of change for probably the first time during the medieval period (p. 38).
(d) Here's another crucial refinement: Aristotle never had a satisfactory explanation of why arrows don't drop like rocks the moment they left their bows. Buriden (1330) offered an alternative explanation: the bow imparts impetus, which then becomes an internal property of the arrow.
(1) Thus, the arrow falls because it meets resistance and because of downward tendency. This is an anticipation of the notion of momentum, which doesn't get a full articulation till Galileo and Newton.
IX. Cosmology: the medieval universe.
A. The medievals accepted Aristotle's model if the universe without the refinements proposed by Ptolomy (because of the complications we've previously mentioned).
B. But they had to change Aristotle's account in one respect to accommodate one telling of Genesis, in which God creates the earth first, then the sky and then waters existing above the firmament.
1. The passage is this:
"And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so."
2. What it suggests is that there is water both above the firmament (between the stars and the realm of God) and below the firmament, as indicated in the following illustration:
X. One progressive suggestion that didn't get any play was that the earth rotates on its axis, so that the movement of the stars becomes merely apparent.
A. But a problem was seen: If you shoot an arrow, it falls back down to where it was shot.
B. Counter-solution that was proposed: Look at what happens on a ship. Maybe the atmosphere travels with the earth as it rotates. But shot down by revelation. But Psalm 92:1 claimed that the earth shall not be moved, so the proponent (Oresme) retracted. Right idea, wrong time.
XI. Astrology remained influential.
A. It was even incorporated into medicine (to explain plagues and the like).
B. Medieval medicine was largely influenced by the rediscovery of the works of Hippocrates and Galen, who understood illness as imbalances between appropriate levels of humors, blood, phlegm, and other bodily substances which are even more disgusting.
C. Besides bleeding, they used herbs to restore balance, and used plants to do things like induce vomiting and diarrhea. All in all, it sounds like a typical medieval medical patient was a real attractive person.
XII. Let's move on a little more. William of Ockham (around 1300) was kind of paradoxical. What does the author say about him? First, what is Ockham famous for? What is Ockham's razor?
A. For instance, motion is not a thing. Moving objects are things that exist in different successive places, and when they do, we call it motion. Surface grammar. Nominalism: Does this bode well or ill for scientific thought?
B. One fundamental concern here underlying a lot of medieval thought is with the consequences of God's omnipotence. You can see that above: if tendencies toward motion is not a thing which is intrinsic to the nature of moving bodies, then God could have created those bodies without those tendencies.
XIII. Now, around the 14th century, the new humanism sets in. What's that?
A. Part of it is a rediscovery of Plato. Remember what we said about the how the theme of bouncing back and forth between Plato and Aristotle.
1. Plato, as we noted, was more mystically inclined than Aristotle. Our ultimate contact with reality, on his telling, consists in a spiritual union with the form of the Good.
2. So, when you think about it, you can see how this might lead some to turn to a kind of magical thinking.
3. One view that became popular among some was that, with the fall from grace in the Garden of Eden, we had become alienated from a world spirit with which God had originally placed us in harmony. And it was really quite hopeless to do what the natural philosopher wanted to do, i.e., describe on a detailed scale the links between causes and effects. Rather, the goal should simply be to use talismans and incantations to re-establish our connection with nature and thus bring about various effects from causes without really understanding them
4. What is the main consequences of this gonna be? Paradoxically, an emphasis on technology rather than theoretical understanding. This is made obvious by the two main goals that the alchemists had. What were they?
XIV: Now comes the reformation of the 15th and 16th centuries, which I'm not going to spend a lot of time on. Someone describe it to the rest of us.
XV: What else, the printing press and movable type, with its obvious effects on scholarship and learning.
XVI: But just as important was the expansion of geographical horizons. This really had an effect on people.
A. There was expanding knowledge of Africa, which people already knew about. Some expanding knowledge of Asia through Marco Polo, but which most people knew about only because of the story of the Magi in the Nativity story. Remember, they brought the myrrh. You gotta have myrrh, man. What baby shower is complete without myrrh?
B. But, obviously, it’s the alleged "discovery" of the New World by Columbus and the subsequent recognition that it constitutes and entirely new continent by Europeans that really makes people think. If the church and the learned men and the Bible hadn't predicted this, then what else didn't they know?
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