HON 280 -- LECTURE SIX (ARISTOTLE)
THE DEVELOPMENT OF SCIENCE
Aristotle (384 BCE). From Macedon in the North. Teacher of
Alexander the Great.
I. How was he different from Plato with regards to the existence
of the Forms.
1. Forms do not exist outside their instances. And they are
really nothing more than the defining natures of these
objects, or their inner structures.
A. At one point, Aristotle dealt with the example of
Socrates' snub nose. He claims, the snubness of the
nose is not a general property which exists
independently of the nose in which other noses may
participate. It is merely an aspect of Socrates' nose
which only exists in its instances.
II. Consequences of this difference.
A. Aristotle didn't think that empirical reality was
somehow unreal, and thus paid much more attention to
its details.
B. When he tried to account for the natures of natural
things, he didn't appeal to divine plans or purposes. He
did not posit a demiurge. Rather, for him, the behavior
of a thing is determined by its internal nature.
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C. Aristotle characterized the natures of natural
objects in terms of various new kinds of distinctions
he invented out of whole cloth for the occasion.
(a) Four different kinds of explanations, or causes
(or becauses) (examples on p. 12 of Gregory
text).
(i) Material Cause
(ii) Formal Cause
(iii) Efficient Cause
(iv) Final Cause
(b) To describe the course of an object over its
lifetime is to describe its transition from
potentiality to actuality.
III. How are these categories used to described the growth and
development of a natural object? Consider the growth of an
acorn into an oak tree.
A. The material cause of the oak tree is the wood out
of which it is composed.
B. The Formal cause of the oak tree is the inbuilt
features of its defining structural organization (today
we might say its DNA)
C. The efficient cause of the oak tree is the other two
oak trees who publicly mated (as trees are prone to do)
to create the acorn from which it grew.
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D. The final cause of the oak tree is the end state
toward which oak tree growth and development tends,
to become a healthy and mature member of its kind.
E. There is, moreover, a special relation between the
tree's final and formal cause: Its formal cause is best
understood as an indwelling of its final cause. This is
to say that it part of the defining structural nature of
the oak tree to grow and develop into a healthy and
mature member of its kind.
F. Also, as the formal cause operates, the organism
changes from acorn to oak tree, finally realizing its
final cause. It goes from being potentially an oak tree
to becoming actually an oak tree.
IV. The previous material is largely directed to the ends of
biological explanation. But it helps to flesh out Aristotle's
physics, also.
1. On his account, motion is explained by the fact that
natural substances have natural places. For instance,
physical bodies belong at the geometric center of the
universe. This explains why they fall to the earth. Water
naturally floats on water. Air naturally rises above water.
Fire naturally belongs above air, as evidenced by an open
flame's seeming tendency to lick up at the sky when
burning.
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2. They are not ordered this simply, in fact, only because of
the disruption imparted to the elements by the motion
generated by the movements of the universe around the
earth.
V. Aristotle's physics also supplements his account of
astronomy. But for this he needs to add a fifth element,
quintessence, from which the heavens are made.
1. Remember Eudoxus (previous lecture). He devised an
ingenious planetary system based on spheres designed to
account for the fact that the moon, sun and planets don't
move as regularly as they would if they simply traveled in
perfect concentric spheres around the earth.
A. The overall geometry of the universe:
(a) Earth is in the geomantic center.
(b) Around earth are 27 concentric spheres,
all rotating around the earth.
(c) The last sphere caries the fixed stars; the
others are the sun, the moon, and the five
planets.
(d) Each planet needs four spheres apiece.
The sun and moon need three spheres apiece
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B. Consider the moon. (Bear in mind, I'm not asking
you to remember all the details of this. Just get the
idea of the general mechanism and a sense of just how
complicated it is.)
(a) The outer sphere rotates each day with
the stars tacked onto the inside of it, and
with axis perpendicular to the zodiac.
(b) The next middle sphere rotates on a
circle at an angle to the zodiac circle from
east to west.
(c) The inner sphere rotates about an axis
inclined to the axis of the second at an angle
equal to the highest latitude attained by the
moon, and from west to east. The moon is
fixed on the great circle at this angle.
(d) It looks like this:
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C. Aristotle took this, tweaked it till he needed more than
50 spheres. Most of these are intended to help the projected
movements come out right. But included in this number are
also a set of crystalline spheres between those carrying the
planets, to keep them from disturbing each other.
D. Drastically simplified, it looked like this:
E. As mentioned above, all substances here are where they
are supposed to be. Each substance has a natural place.
Earth belongs at the center, water belongs on top of earth,
etc. But the elements get mixed up by the movement of the
spheres, generated by the prime mover at the periphery.
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F. At the center, the stuff is heaviest and has the least actuality
and the greatest potentiality (i.e., greatest susceptibility to
change.) At the periphery are the stars and the prime mover,
which are very light and have the greatest actuality and least
potentiality (i.e., they act on other things and are least
susceptible to change).
HON 280 -- LECTURE SIX (HELLENISM)
THE DEVELOPMENT OF SCIENCE
I. Last time, we finished with Aristotle. Note that certain aspects
of his cosmology exist in religious thought even now (think
about how children think about heaven and hell. It was formally
dominant even more powerfully (think about Dante's trilogy).
II. Hellenism was the period of time running from the death of
Alexander the Awesome (323 BCE) to the fall of Greek political
power to the Romans. The latter date is differently reckoned by
different historians. Some reckon it to be the year when the
Romans conquered the Greek heartland 146 BCE). Others
reckon it to be the year that Rome conquered Egypt (30BC),
since Egypt was the last remaining influential bastion of Greek
civilization (having been conquered by Alexander).
III. During this period, Aristotelian physics faced competition
from the atomists. Remember them? Their central doctrines
were: (1) all that exist are differently assembled collections of
atoms in the void, (2) the ways in which these atoms assemble
and disassemble are governed by chance collisions, not
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purpose). That is, things happen in nature due to causes, NOT
for reasons.
IV. The major advocate of atomism during this time was
Epicurus (270 BCE). Interestingly, he offered atomism as the
basis of a moral doctrine, or at least as a doctrine telling us how
best to live.
Specifically, he thought that atomism alleviated two central
obstacles to the good life:
(1) Fear of the gods.
(2) Fear of death.
(Refer here to your own lecture notes for details.)
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