Download HON 280 -- LECTURE NINE (Ptolemy to copernicus) THE

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.
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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,
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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.
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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.
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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?
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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
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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.
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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:
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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
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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.
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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
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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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