Epistemologists: 2 schools of thought.
1. Rationalists
·
Trust in a priori reason and
introspection.
·
Distrust the senses or sensory
knowledge.
·
Some ideas (the most reliable) are
innate, born in us.
Ex: Plato, Anselm and Descartes
Continental Rationalists: 3 prominent
rationalists at the time
René
Descartes (French- 1596-1650)
Baruch Spinoza (Portuguese/Dutch 1632-1677)
Gottfried Leibniz (German- 1646-1716)
2. Empiricists
·
The only way to acquire knowledge is
through the senses (nothing is in the mind without first being in the senses)
·
Deny the existence of innate ideas;
·
Share a certain confidence in reason
but mostly to be legitimate any idea must trace back to or relate to
experience.
Ex: Aristotle, St. Thomas Aquinas
British Empiricists: 3 prominent
empiricists
John
Locke (English 1632-1704)
George Berkeley (Irish 1685-1753)
David Hume (Scottish 1711-1776)
Epistemology - the branch of philosophy that is concerned with knowledge
and justification
Rene Descartes:
Important contributor to both science
and math, plus a devout Christian/ Catholic. He contributed to both science and
mathematical foundations, most notably the "Cartesian plane."'
Descartes was a contemporary - Galileo
Galilei (1564 - 1642). The latter is considered
founder of Modern Physics. Among other
things he used the telescope to investigate solar system.
Dispute at the time: the nature of the
heavens and earth
Geocentric
theory - earth at center and everything
revolves around it (church supported this theory).
Heliocentric
theory - sun at center (Copernicus theory)
Mars in Retrograde:
Animated illustration representing
retrograde motion from a geocentric (earth - centered) perspective.
Ptolemy to the Rescue
http://zebu.uoregon.edu/disted/ph301/hlec05.html
Ptolemaic System
Simulator
http://astro.unl.edu/naap/ssm/animations/ptolemaic.swf
Retrograde Motion and the Opposition of
Mars
https://www.youtube.com/watch?v=72FrZz_zJFU
·
Two views had nearly equal
explanatory/predictive power (by the time of Galileo[1]),
but Heliocentric theory much more elegant/simple.
·
Still, the moon DOES orbit earth- on
either account.
Supporters of the heliocentric pointed
out that their rival theory was inconsistent.
It claimed that everything obits the sun… except the moon. By contrast, the geocentric theory was more
consistent: everything, including the moon, orbited the earth. Thus the fact that everyone had to agree that
the moon orbits Earth and not the sun was seen as the last bit of evidence
recommending the geocentric theory over the heliocentric theory.
Galileo was commissioned by Pope Urban
VIII to write an analysis thesis comparing the 2 theories. But when Galileo looked at other planets
through the newly invented telescope, he found that other planets had moons of their
own. Therefore there was nothing exceptional about the moon orbiting the
Earth. In fact the new findings were more consistent with heliocentric
theory. This really removed the last bit of support recommending the geocentric
model over the heliocentric model.
Galileo came down on the side of the
heliocentric theory and defended his views in Dialogue Concerning the Two Chief World Systems (1632), [2]
In 1633, Galileo was convicted of
"grave suspicion of heresy" based on the book, which was then placed
on the Index of Forbidden Books It was
not removed from that list 1835. He was
forced to recant, and lived under house arrest for the rest of his life.[3]
Galileo:
‘The Bible shows the way to go to heaven, not the way the heavens go.”[4]
This was a HUGE revolution in science/
knowledge in Western culture. Humans had been wrong, and wrong in some
pretty fundamental ways, for thousands of year. Plus. A lot of other long
held beliefs were being over turned. (e.g. "Objects of different
weights fall at different rates of speed."- Aristotle said so; everyone
believed he was right. Galileo proved Aristotle was wrong, and always had
been.) [5]
Descartes was trying to deal with these
the new revolutions. He was a champion of the new “science.” But he was concerned about the implications
of a “godless” science.
Towards the end of Meditation II, in
the midst of the Wax Argument, Descartes criticizes the assumption that it is
the senses that give us certain knowledge about the world. For example, he
says, on looking out of the window down into the street below, he sees various
men dressed in hats and cloaks walking by.
In
this case I do not fail to say that I see the men themselves, just as I say
that I see the wax; and yet what do I see from the window beyond hats and
cloaks that might cover artificial machines, whose motions might be determined
by springs? But I judge that there are human beings from these appearances, and
thus I comprehend, by the faculty of judgment alone which is in the mind, what
I believed I saw with my eyes.[6]
Attempted reconciliation between
"new" Science (Galileo) and established Christian World View
With the rise of modern science, the
modern mechanical view of reality was an absolutely unavoidable
consideration for any metaphysician. Unmodified, this world view seems to
suggest that reality consisted of nothing other than inanimate matter in motion
governed by impersonal mathematical laws.
Descartes resisted such a view of reality:
1)
Science cannot (must not) replace the world view of Christianity with a Godless
amoral universe of "matter in motion." (a.k.a.
Thomas Hobbes- note similarity to early pre-Socratics philosophers who did not
see morality or purpose and fundamental to any scientific/ philosophical
understanding of the cosmos.)
2)
Science cannot (must not) reduce human existence ‑in particular the
thinking "self" ‑to just a machine[7].
Descartes begins his inquiry seeking a
certain foundation for knowledge and science.
In the end he concluded that our assurance in the reliability of our own
knowledge claims rests ultimately on our confidence in the goodness of and all-powerful
God.
Descartes is dealing with all the
revolutions in our inherited Greek science.
Further, as a mathematician, he was
impressed by Greek math (compare to lousy Greek physics and science and
medicine)
·
Questioned: Why the dissimilarity? (Why
was Greek science crap, but Greek math still completely solid?)
·
Decided it was a question of structure.
o Math had a foundation and method[8]
while science had neither.
·
Sought a foundation for all
knowledge:
He therefore insisted upon perfect
certainty and mathematical deduction as the legitimate methodology. This is where modern metaphysics begin and
importantly, what is sought is a relationship among propositions. This gives modern metaphysics an inherently
epistemological and ultimately linguistic orientation.
Quest for Certainty
His plan was to build up from a certain,
indubitable truth or set of certain truths an edifice of knowledge that would
not be vulnerable to the kinds of errors and revolutions plaguing medieval
science.
2 parts to Descartes
1.
Methodological Doubt - negative project
2.
Reconstruct Knowledge - positive project - everything founded on me then God
then higher up reason.
Think
of those Home Improvement Shows on GGTV.
The first thing the remodelers need to do is tear down. The next thing that will do is the build
out. So first Descartes goes in with a
sledge hammer, then with bricks and mortar.
Methodological Doubt (Sledge Hammer)
To find a belief or beliefs that were
indubitable, he tried to doubt the beliefs he had. If he found one he
couldn’t doubt, he would have found his certain/ indubitable belief.
Set the bar very high- "beyond a
shadow of a doubt.[9]"
3 categories for his beliefs (divided according
to the way he came to believe them)
1.
beliefs on a basis of authority
2.
beliefs based on own experience
3.
beliefs based on reason
Finds each category doubt-able.
#1 is doubt-able because they might be
lying or mistaken.
#2 is doubt-able because my senses are
not sufficiently keyed into reality and therefore not sufficiently reliable as
dream experience proves.
#3 is doubt-able because I cannot be
certain that an evil demon does not exist who is so powerful that he could fool
even my reason. If such a being is possible (and there is no reason to
suppose he isn’t) then I could be wrong when I draw conclusions based on
reason.
Is ANYTHING indubitable?!?
Might he even be wrong in thinking that
he exists? Might the evil demon be so
powerful that he chould even fool Descartes even
about the reality of his own existence?
Descartes tries to doubt his own
existence:
“I
doubt that I…
Hmmm…..
Let me try again….
“I
doubt that I…
Impossible!
In the very act of doubting- or any
kind of thinking for that matter, I know
that I am.
Or famously:
"Cogito ergo sum."
"I think therefore I am"
This is NOT an argument, but rather it is known because it is a “clear and
distinct” idea before the mind’s eye.
OK, but... where do we go from
there? Descartes seems stuck in Solipsism, which was NOT the plan remember.
Solipsism- belief that one is the only thing that exists in the universe and everything else is part of imagination
How do we
commence the “build out” when all, or nearly all our tools are boxed up and out
of reach?
Descartes Rationalist Re-Construction
of Knowledge (Bricks and mortar)
1.
I think therefore I am.
2.
I am thinking thing (at least a mind).
Descartes Theory
of Mind: (see notes at end)
3.
I am thing with thoughts.
Before you think, “Whoop de doo; big deal.” remember, he wants
to take baby-steps.
Next:
·
Descartes wants to get rid of the
possibility of an evil demon. If he doesn't
have to worry about the possibility of an evil demon, he could trust beliefs
based on reason again.
·
Only one thing is big and good
enough to do the job: God.
·
He therefore attempts to prove that God
exists.
He knows that he is a thinking being;
therefore he is a thing with thoughts and one happens to be the thought of God.
Argument of existence of God
|
Number |
Proposition |
Justification |
|
1.
|
I have the idea of a perfect being. |
Given by introspection |
|
2.
|
I have a perfect idea. |
Follows from #1 |
|
3.
|
An effect cannot be greater than its
cause. |
Metaphysical or physical principle |
|
4.
|
I am not perfect. |
Given by introspection |
|
5.
|
I cannot be the cause of my perfect
idea. |
3 & 4 |
|
6.
|
Only a perfect being can cause a
perfect idea. |
3 |
|
7.
|
A perfect being exists. |
2&6 |
|
8.
|
God exists |
7 |
Trying to go from the fact that he has
an idea of God to certain knowledge that God exists. Since I have this idea the
only thing that can explain this idea is God. This is kind of a cosmological
argument for the existence of God.
This means:
1. There is no evil demon because God
is a good, etc. Therefore we can trust reason (logic and math).
2. Because God is good and we have been
created by Him, made for the world and the world for us, we CAN trust our
senses so long as we do not extend our will to believe beyond what the evidence
warrants. Therefore we can trust the testimony of our senses, though not with
the same degree of confidence that we trust our reason (empirical knowledge).
Note: He never attempts to restore authority as a mode of
justification. Individual authority replaces institutional
authority. Radical idea to Thomistic Scholasticism. Ushering in the
Modern Era. This is one of the reasons that Descartes is called the first
Modern Philosopher.
Our trust in our own mind and in our own
senses depends on trust in a benevolent God. If we didn't live in a
divinely governed benevolent universe we would have no reason to trust our mind
or to trust our senses. If you give up on God you have to give up of your
own ability to know. Absent the notion of God on what grounds can you
trust your reasons or your senses?
Problems with the Argument Offered
Above:
3
major problems with Descartes argument
1.
Do you really have a perfect idea of
God or perhaps do you have an imperfect idea of a perfect being? If the idea is
imperfect then it wasn't caused by God. He could have come up with it.
2.
“An effect cannot be greater than its
cause.” This is either a physical or a metaphysical principle. But If he is doubting his senses why is he using a physical
principle? If he is doubting his reason why is he using a metaphysical principle?
3.
It’s an Argument. But, if
doubting reason one cannot use reason to justify reason. That’s begging
the question. (Circular)
Descartes claims that the mind is
different from the body because they each have different properties. If X is identical to y then x and y must have
all properties in common.[10] Mind
and Body do not have all the same properties in common. This, he thinks, proves that the two are distinct.
For instance, one can doubt one has a
body but one cannot doubt one has a mind. Thus the existence of body is
doubtable while the existence of the mind is not.
Note: But maybe I don’t doubt the Peter Parker is meeting me
for tea this afternoon, but I do doubt that Spiderman is meeting me for
tea. Does this prove that Peter Parker
is not Spiderman?
1. Further, the mind (thoughts, ideas) has
no location; bodies always do.
2. Mind is private (only I can feel my pain), but bodies are public (everyone
can see it just as well as I can, perhaps even better –back of my head).
3. I have privileged access to my mind (better than anyone else) but no
privileged access to my body.
4. My beliefs about what’s going on in my
mind are incorrigible, whereas my
beliefs about what is going on in my body are corrigible.
Thus, to explain everything we are
aware of, we must posit 2 kinds of substances –besides God (mind/body dualist)
1. material
2. immaterial
(mental)
They are radically different.
Also, since he conceives of matter as
essentially unthinking, and conceives of himself as essentially a thinking
thing, he cannot be identical with his body.
And, firstly,
because I know that all which I clearly and distinctly conceive can be produced
by God exactly as I conceive it, it is sufficient that I am able clearly and
distinctly to conceive one thing apart from another, in order to be certain
that the one is different from the other, seeing they may at least be made to
exist separately, by the omnipotence of God; and it matters not by what power
this separation is made, in order to be compelled to judge them different; and,
therefore, merely because I know with certitude that I exist, and because, in
the meantime, I do not observe that aught necessarily belongs to my nature or
essence beyond my being a thinking thing, I rightly conclude that my essence
consists only in my being a thinking thing or a substance whose whole essence
or nature is merely thinking]. And although I may, or rather, as I will shortly
say, although I certainly do possess a body with which I am very closely
conjoined; nevertheless, because, on the one hand, I have a clear and distinct
idea of myself, in as far as I am only a thinking and unextended
thing, and as, on the other hand, I possess a distinct idea of body, in as far
as it is only an extended and unthinking thing, it is certain that I, that is,
my mind, by which I am what I am], is entirely and truly distinct from my body,
and may exist without it.”[11]
The most difficult problem of
Descartes' philosophy of mind was the relationship between the various
substances. By definition substances are
distinct and independent; interaction would seem to be interdependence and not
logically possible.
How does what is immaterial interact
with what is material? Objection: where
does the mind touch the body?
If really immaterial “you” don't exist
anywhere and yet somehow the dualist believes that “your” mind is making “your”
body (and only your body) move around and responds to its “sensations.”
Also, this seems to violate the
conservation of energy principle form physics since it posits a NON-physical
source of physical energy.
Also, seems to posit a single, unified
conscious ego, but recent discoveries in cognitive science suggest there is no
such single unified ego. (Split Brian Research)
"Substance" -Defined from
Aristotle as "a thing existing in such a manner that it has need of no
other thing in order to exist."
Ontology divided into three unique
"substances.”
NB: Descartes is usually
referred to as a dualist, despite the fact that he claims that there are three
distinct substances.
1. Mental Reality
2. Material Reality
3. God is in a category by Himself
There are two "substances"
in nature: mind and body. They are
utterly distinct and independent.
Principle LI.
“Substance," strictly speaking, for Descartes means "a thing
existing in such a manner that it has need of no other thing in order to
exist" (Principle LI[12]),
In this strict sense, according to
Descartes, only God is really a substance.
"What substance is, and that is a name which we can not attribute in the same sense to God and to his
creatures."
But in a derivative sense
"created substances, whether corporeal or thinking, may be conceived under
this common concept; for they are things which need only the concurrence of God
in order to exist
Principle LII.
"That it may be attributed univocally to the soul and to the body
and how we know that substance."
Principle LIII.
"That each substance has a principal attribute, and
that the attribute of mind is thought, while that of body is extension.
Principle LIV.
"That the nature of body consists ... in extension alone.
Principle XXXIX
"The freedom of the will is
self-evident.
There are 2 kinds of substances
–besides God (mind/body dualist)
·
material
·
immaterial (mental)
They are radically different.
Thus, the mind is immaterial-not a
body, no location, private, incorrigible. Descartes
defines body as non-thinking substance.
With this definition of material substance, think/ consciousness can
only be explained by some other substance, (as Descartes claims occurs with
human beings) of it does NOT occur at all (as Descartes claims with non-human
animals and the rest of the material world.
Descartes on Animals:
In contrast to Aristotle, Descartes'
mechanistic philosophy offered the idea of “mechanical reflex” to explain the
behavior of nonhuman animals. This view sees animals as reflex-driven machines,
with no intellectual capacities.
However, he did not deny that these animals engaged in sensation and
perception behavior. Rather is claims
was that mechanistic explanations were sufficient to explain these aspects of
animal behavior. This is similar to
Aristotle’s distinction between instinct (which he took to be largely
corporeal) and reason (which, at least in its highest function, was not).
Descartes
himself did practiced and advocated vivisection (Descartes, Letter to Plempius, Feb 15 1638), and wrote in correspondence that
the mechanical understanding of animals absolved people of any guilt for
killing and eating animals. Mechanists who followed him (e.g. Malebranche) used
Descartes' denial of reason and a soul to animals as a rationale for their
belief that animals were incapable of suffering or emotion, and did not deserve
moral consideration — justifying vivisection and other brutal treatment (see
Olson 1990, p. 39–40, for support of this claim). The idea that animal behavior
is purely reflexive may also have served to diminish interest in treating
behavior as a target of careful study in its own right.[13]
[1] Initially, Copernicus had insisted that the obits of the planets, etc. were perfect circles, as Aristotle had taught. But when you try to create a heliocentric model with circular obits, it didn’t really work all that well, not as well as the geocentric model it was trying to replace. It wasn’t until Johannes Kepler, with great reluctance, allowed that the obits were ellipses, not circles, that he was able to develop a model that rivaled the geocentric model with respect to predictive ability.
[2]It did not help Galileo politically that he names the character who defends the Aristotelian/ Ptolemaic model “Simplicio.”, Supposedly named after him after Simplicius of Cilicia, , a sixth-century commentator on Aristotle, but it was suspected the name was a double entendre, as the Italian for "simple" (as in "simpleton" "semplice"). Some have suggested that the Pope, himself a vocal supporter of the Ptolemaic model, took personal offense to this.
[3] In retrospect, Galileo may have gotten off comparatively easily. In 1600, Giordano Bruno was convicted of being a heretic for believing that the earth moved about the Sun, and that there were many planets throughout the universe where living creations of God existed. Bruno was burnt to death.
[4] Some attribute this to Cardinal Caesar Baronius and it was requoted by Galileo.
[5] Aristotle also said, “Males have more teeth than females in the case of men, sheep, goats, and swine; in the case of other animals observations have not yet been made: but the more teeth they have the more long-lived are they, as a rule, while those are short-lived in proportion that have teeth fewer in number and thinly set.” History of Animals, Book II, Part 3. They do not by the way.
[6] Meditation II, my italics. From the Meditations John Veitch translation used for the online version on PhilosophyOnline.
[7] During the Classical and Medieval periods, anything that was able to “move” on its own was supposed to have an anima, that is, a “soul” which animates it to explain this self-motion. But by now humans have been able to create automatons. Indeed there were, by this point, there is quite a few machines that seems to move on their own, but have no anima, no soul. Might animals and humans be the very same? “Dead” matter that has been cleverly organizes into self-moving systems? The new science seemed strongly to suggest so.
[8] EX: Euclid’s Axioms and Postulates:
First Axiom: Things which are equal to the same thing are also equal to one another.
Second Axiom: If equals are added to equals, the whole are equal.
Third Axiom: If equals be subtracted from equals, the remainders are equal.
Fourth Axiom: Things which coincide with one another are equal to one another.
Fifth Axiom: The whole is greater than the part.
First Postulate: To draw a line from any point to any point.
Second Postulate: To produce a finite straight line continuously in a straight line.
Third Postulate: To describe a circle with any center and distance.
Fourth Postulate: That all right angles are equal to one another.
Fifth Postulate: That, if a straight line falling on two straight lines make the interior angles on the same side less than two right angles, the two straight lines, if produced indefinitely, meet on that side of which are the angles less than the two right angles
[9] Note this is far higher than the evidential standard we bring to bear, even in capital criminal murder cases. In these we require guilt be proven beyond a reasonable doubt. Descartes, by contrast, is seeking assurance of the truth of a claim beyond a shadow of a doubt.
[10] This principle is formalized by Leibnitz and others as the “Principle of the Indiscernibility of Identicals.”
[11] Meditation 9, paragraph 6
[12] The Principles of Philosophy, trans. Anscombe and Geach)