1160: Enlightenment and Human Understanding
Sept. 10th: 1st Lecture
master’s office at vanier
Term work: 4 in class tests. will give questions ahead of time
1st test: end of october
Course kit: Regulae: rules for the direction of understanding. he wrote 36, we will study
read pgs 1-49
Course kit: Principles of Philosophy: teaching manual for those who will be teaching
* note: not course kit numbers! original book numbers.
-replies to objections II: pgs 30-52
Meditations on First Philosophy:
Immanuel Kant: after descartes: only 3 questions can be raised in a philosophic
1. What can I know? epistemology (the study of knowledge--knowing)
2. What ought I to do? duties and responsibilities: ethics, moral philosophy
3. this question follows from #2--if you do the right thing, you should recieve some sort
of reward: What can I hope for? eschatology (the study of last things). is there an
afterlife? will you be rewarded?
in this course, only look at #2 with Hobbes, and d/n look at #3 in this course
1 the period: the enlightenment: 17th and 18th centuries
enlightenment thinkers: general characteristic: dissatisfied with learning of the past.
thought of themselves as revolutionaries. outright rejection of the learning of the past--
the learning of the past will corrupt you.
did not seem themselves as part of a chain of learning going back to the greeks and the
why were they dissatisfied with learning of the past? (these were not university-
medieval period: all medieval thinkers were doing exegesis: they studied texts:
all that happened was that the thinkers were exegeting.
-the bible: revealed truth
-plato and aristotle
medieval thinkers: not two sets of truths, same truths: plato and Aristotle from reason,
bible from revelation.
-bible and plato and aristotle contained all truths that humans can and should know.
but: sometimes the bible and p&a contradicted each other, and p&a contradicted each
aquinas: the great synthesizes: task: to reconcile bible with p&a
descartes: entire dissatisfaction with this way of proceeding
scientific revolution underway: newton, Kepler, etc
-scientists attempted to prove what it was they were concerned with
what makes proof possible? need an accepted method of investigation
2 2 kinds of science:
-incredible strides in:
-1. mathematics (descartes invented algebra)
physical sciences: astronomy, medicine, physics
medieval thinkers had no method: c/n establish truth
it may be that there are truths in bible and p&a
failure of the past: failure to address method.
descartes: no such thing as philosophy, there were philosophies
in order for this revolution to take place, we need to focus on method
-can we learn from mathematicians and science?
-physical sciences use observation: experiments. depend on observations
descartes argued: difficulty with physical sciences: level of certainty that emerged from
these experiments. most that can be said: findings are probable. never certain.--always
room for another revolution in science.
descartes: i want knowledge that is true for all time. eternal truths. turned to
mathematics. the truths in mathematics are eternally true.
therefore: mathematics is the only area that will be fruitful. we are not interested in the
physical sciences--we are interested in the mathematical sciences.
Regulae pg 3:
rule 2: only those objects should engage our attention
half way down pg: “thus in accordance with the above rule or maxim we reject all such
probable knowledge, and make it a rule to trust only what is indubitable”
bottom of pg: “consequently, if we think of the sciences already discovered, arithmatic
and geometry yeild indubitable knowledge...”
3 pg 5: “but one conclusion....direct road toward truth...we should busy ourselves with no
other...except arithmatic and geometry”
-philosophy is going to copy arithmatic and geometry
pg 25, last para, top of 26:
“ this method of ours resembles...the...mechanical crafts which d/n need the aid of
anything outside of them...own instruments...forced to use at first a hard stone or rough
lump of iron (things nature has provided). rock instead of hammer. wood instead of
tongs. thus equipped, he would not then set out at once in attempt to...he would first of
all fashon a proper hammer, proper tongs...since thus at the outset...rough
precents...we should not forthwith we try...we must first employ...are wrong to demand”
in the beginning of mechanical crafts there were no proper tools. started with primitive
items in nature--used these primitive items to make better tools. once they had better
tools, they could practice their craft. philosophy must proceed in exactly the same way.
mathematics had no book or manuel on method. yet, mathematical truths were found.
seeds or germs of method: b/cm known to the ancient greeks and others--correspond to
‘primitive tools’. given there has been advance in mathematics without method? seeds
or germs of mathematical learning. how did they become aware of these? these
seeds/germs are already in our minds. innate.
pg 10, course kit:
“since the usefullness of this method...i am quite ready to believe...nature even
conducting them to it. for the human mind has in it something we may call divine...first
germs of useful thought...bear fruit of their own accord...simplest sciences give us an
...these two methods...inborn principle”
these seeds were given to us by GOD. we can now develop a method
PROBLEMS WITH DESCARTES METHOD
4 in regulae: all references to mathematics: held to be certain, indubitable, eternal
-we can emulate the method of mathematics to come up with a method of learning
-rules 1-4: sets out how mathematicians proceed
-rules 5-12: adaptation to learning generally--how to make them work beyond
-meditations pg 48:
1st para: “that is probably why our reasoning is not unjust...falsity or uncertainty”
2nd para: “nevertheless...He does permit this”
-entertains the possibility of deciept in mathematics
pg 59 & top of pg 60:
Principles of philosophy
“we shall also doubt of all other things, even of the proofs of mathematics...God who
created us can do anything he wants”
what are we to do with this dichotomy?
regulae: mathematics is certain
elsewhere: god can deceive us
main focus of course: epistemology
Descartes concerned with areas of epistemology:
1. our cognitive faculties--what enables us to know: knowing faculties in our brain
2. levels of certainty in pursuit of knowledge (b/w indubitability and ignorance)
3. limits of human knowledge: what can we know, and what can’t we know (Can we
know God? is God an object of knowledge?)
4. the nature of knowledge
(mathematical knowledge is hierarchical: some things have to be known before other
things can be known)
5 axiom of equality: things equal to the same thing are equal to each other
5. objects of knowledge. what are mathematicians studying?
isosceles triangle: two opposing sides are equal length--base angles are equal.
A. -diagram is imperfect
B. -mathematician is not talking about the isosceles triangle on the board, but rather the
triangle as it is thought (not as it is drawn)
-objects of mathematics (what) is not a picture on the board, but the thought of a
-the objects of mathematics are not empirical.
-even if there were no triangles in existence, it would still be true that the base angles
are equal. the truths do not pertain to physical objects.
Sept. 24th: second lecture
first test: end of october: 22nd or 29th
-all enlightenment figures, including descartes, thought were creating a break from the
-not indebted to past, not continuing past
-saw selves as revolutionaries
-would change state of learning...for all time...
-previous: revelation (bible) and reason (plato, aristotle)--exegesis
-rejected study of bible as containing all truths
-crit: no method for distinguishing truths
-hope and confidence: rise of science: newton, kepler, galileo--making progress
through a new method. systematic.
-learning generally would need to emulate the sciences
6 -which sciences would you emulate?
empirical sciences: always have recourse to observation: physics, astronomy
-did not generate knowledge
-probably not certain (if were certain could not be overthrown). revolutions in
a priori sciences: make claims prior to experience: mathematics: arithmetic and
geometry (d. founder of algebra)
-only here was certainty achievable
-the kind of truth is considered eternal (will never change)
-2+2=4: truths are indubitable
any truth in the empirical sciences (eg: for every action there is an equal and opposite
reaction)--can believe is false, even if not.
in a priori sciences: the opposite isn’t even thinkable
-the denial of the claim is not thinkable
how to proceed?
1. figure out what mathematicians do: find out about their method. how do they solve
-no book on method... therefore took it upon himself to write this: regulae
-take what mathematicians do, and make it an object of study--what do m’s do when
they do math? math b/cms the object of study (rules 1-4)
-rules 5-12: attempt to adapts rules of math to generation of universal method
characterize break w past:
1. which discipline is supreme?
medieval thinkers: believed were tied to church and doing the church’s business
-theology the supreme form of learning, unchallengable
enlightenment thinkers: considered selves completely autonomous, therefore
emancipated from the church
-philosophy could judge theology--claims of the church had to be adjudicated by
-sit in judgement
-philosophy b/cms the supreme science and theology is downgraded
medieval thinkers: god
enlightenment: if god is not the first item that needs to be studied, what is the proper
first object of study? human nature.
-basing view on mathematics: what is the origin of a mathematical truth? we don’t make
them up. (law c/n decree 2+2=5). they are not created by us. there is no obvious creator
to mathematic truths
-concluded: mathematics come from the mind studying itself. mental. d/n come from the
physical world. they come from us.
-they come from human nature.
-conclusion: if learning generally, and phil in partic, are to undergo a revolution,
it must be the case that the truth of phil and learning must also come from human
-in order to make inroads we need to study ourselves.
theological view: causality tied to theology
non-theological explanations: difference sense of causality.
-aristotle: figured out causality: if you are going to build smthg--what are the causal
factors? bricks, mortar, copper (material stuff) the material cause but bricks won’t build
themselves, the efficient cause (need a builder) always pushes. but need a plan--put
into proper order: formal cause, blueprint or plan. final causality: purpose for building
-in order to understand anything, need to understand 4 types of cause
-if you believe in god and responsible for everything in the world, final causality, guides
all causal inquiries
if you have a theological explanation, your inquiry must begin with WHY.
-why questions presuppose an intellect behind what you are investigating.
8 on the other hand...
HOW? becomes the new question.
efficient causality seeks: causal explanation in terms of pushes
-presupposition in efficient causality: world is a type of machine--guided by causal
-final causality ceases to become important
med: all truths have already been revealed
enlight: we d/n possess all truths. there are new truths to be discovered
med: if you think there is a god who created you, your view of yourself in relationship to
other pp, wrld, god, all need to be understood (what does god want of me, etc) need to
understand self in relation to theological system
enlight: rethink rel. to self, others, world, god: rethinking of man’s place in the wrld.
CK 210-211: scheme for learning: “Following on this....
-after code of ethics, should study logic, not that of the Schools (all aristotelian--wrote
first book on logic--none others for 1500 yrs) BUT logic to discover things we don’t
know. (practice on math)
-in aristotelian logic: syllogism: two premises and an a conclusion:
all men are mortal
socrates are a man
therefore socrates is mortal
bothered descartes: syllogistic logic is syntactical
-rules for the manipulation of symbols
9 -in case of syllogistic argument: conclusion of arg never give you new knowledge
-nothing new is given. all that is given is the manipulation of the symbols
-conclusion already implicit. only made explicit. therefore never learn anything. can only
teach others what you already know. (can only be a pedagogical device)
-not suited to revolution and discovery of new truths
we need a logic of discovery:
-teaches us how to direct our reason : kno. which he is seeking is in the mind. not
empirical. already in the mind. a priori. all kno we need is already in our minds, just as
all the math we need is already in our minds.
-philosophers need to bring out kno in mind which already possesses it.
-mathematician: guiding our minds to the relationships that are relevant to solving a
-attempt to give you smthing new (but already in minds) teaches the mind how to seek
the kno that is already in the mind
aristotle: a book which studies everything rather than particular things
-the conditions which holds of things generally. what are the general features of
existence. put after a’s work on physics.
descartes: should study after logic of discovery: metaphysics studies first principles of
human knowledge. what must be known before anything else can be known.
-contained in meditations: first principles of hu. kno.--what needs to be known before
anything else to be known
out of which springs the branches: medicine, mechanics (how the world works), morals
beginning of revolution: paying attn to mathematics: why does math always yield know?
CK pgs 3, 4, 5
10 pg 3: “thus in accordance...”
pg 5: “but one consideration...certainty equal to the proof of arithmatic and geometry...”
WHY DOES D THINK THAT MATHEMATICS IS CERTAIN?
1. (pg 4, bottom) “But now let us proceed...deduction c/n be erroneous...
-mistakes in math either: premise incorrect, or were not paying proper attn to the
-error in math are always human errors
-reasoning in math is infallible--the actual process of reasoning in math is infallible.
-error is always human error
-therefore must properly prepare you mind
2. (pg. 5), 2nd para: “this furnishes us with...the former alone deal with an object...so
pure and uncomplicated that they need make no assumptions...”
-mathematical objects are pure and uncomplicated: thought of isosceles triangle, or
right angle triangle
-figures in the world can only approximate what we are actually thinking about. no
true triangles in nature. only true triangles are in the mind.
-true objects of math are non-empirical
-”PURE”: means a priori. does not derive from observation.
-”UNCOMPLICATED”: can always add to or take away from the thought of an empirical
object. empirical objects, as they are thought, are subject to the mind’s control. because
of that you can never be certain what is actually in the kitchen at any given time. have
no control over physical objects as you are thinking them.
-BUT: mathematical objects: content is fixed. “fixed natures.” no room for uncertainty.
certainty of math: 1. reasoning is infallible. 2. object has a fixed nature
OCT 1ST LECTURE:
11 1st test: Oct. 29th
-secondary sources: book or article--not internet--on descartes
-selected bibliography in meditations book
-a book about the primary source
-use: to inform you on other views: 1. explain difficult parts of the text (exegesis) 2.
elaboration--illustrate importance. 3. reveal inconsistencies. 4. offer criticisms of the
for test: select one author--integrate what he/she says into your answer. discuss
relevance of 2ndary source to your answer. (c/n use tweyman as secondary source)
the relevance of m. to the cartesian enterprise
pg. 4 & 5 CK: exclusive to the R.
-where does the certainty of m. come from?
-”But now let us proceed...”
-yes, there are errors in m. but the mind, in reasoning, is never at fault. the rational
processes which give rise to m. are never at fault. the mind is faultless.
2 sources of error:
1. i. inadvertence (lack of attn). ii. lack of understanding the premises.
2. m & g. alone deal with an object pure and uncomplicated: a priori, non-empirical, in
the mind already. it is never studying the external wrld. no empirical content. i. nothing
depends upon the uncertain senses. ii. cannot leave anything out of a m. idea. cannot
be changed--cannot be added to or subtracted from.
this is where we can have certainty.
what are these faculties?
pg. 7 CK: “But lest we...”
12 only 2 ways to know: intuition and deduction
pg. 7 CK: “By intuition I understand..”
-light of reason: given to us by g-d. like a flashlight. in order for us to see them
-intuition: a cognitive faculty give to us by g-d. points to things we can know.
when 2 things are related, the related objects called relata, singluar relatum: focus of
intuition is to see connection b/w to relata. connections sought all a priori.
pg. 7: last para: “This evidence...”
pg. 8: “Hence now we are in a position...”
deduction: moving down frm 1st principles to a conclusion.
axiom of equality
-in deduction: can only attend to one thing at a time--no way to prove the certainty of
memory. therefore, always an element of uncertainty.
1. true, certain route to knowledge is intuition--infallible
2. deduction can be questioned
3. but...it is possible to improve the sluggishness of memory: go over the steps
repetitively until you could comprehend the entire proof as a single intuition.
-since each step is intuition, there is only one cognitive faculty in knowledge: intuition.
pg. 19, rule VII
“It is necessary to obey...”
13 pg. 10.
“Since then the usefulness...”
-g-d and nature the same thing for d.
-all tools for m., inferences, etc, have come from g-d
-progress in the ancients illustrates these divine seeds
...leaving the R...
m. beyond the R...
-R: written frm perspective of mathematicians: concerned with method
-but...in meditations, and p.o.p. d. writes as a philosopher (not a mathematician)
-level of certainty required by phil. exceeds of that sought by m-tican.
Med. pg 48:
1st para: “why our reasoning is not unjust...”
2nd para: “nevertheless...”
3rd. para: non-believers
pg. 59 & 60
“But when I took anything...”
why m. is dubitable:
A. when two parties disagree on a m. answer
1. confidence is equal: what persuades each of them that they go the right answer?
2. psychological component in m.--irresistibility.
3. psych irresistibility is unreliable
4. but p.i. is the reason we accept mathematical truths--therefore m. truths are
what if everyone agreed?
-if there is g-d, who is a deceiver, power to have the mind get the wrong answer.
objection against atheists
-g-d’s omnipotence (believers)
-non-believers: cause of your existence must be finite--cannot have infinite power.
-your ‘finite cause’: would need to believe it intended you to reach the truth. any finite
cause, despite its intentions, cannot fully guarantee the effect it has brought about.
-atheists have no further guarantee of truth.
R: m. is certain
Med: m. is dubitable
aim of M:
-CK 211--1/3 way down: “then when he has acquired a certain skill...”
Med: uncover 1st principles of hu. kno. & learning
Med. pg 102: “for there is this difference b/w these two cases...”
-quest for 1st principles is different in geometry and metaphysics. search c/n be the
-1st principles of geometry never conflict with the senses.
-but...if you try to understand yourself empirically, it is identical with your body
but: self is conjunction of mind and body. to ordinary c/s is possible to prove truth of
-ordinary c/s learns about g-d through experience.
-if true idea of g-d brought to pp tied to sense, they would reject it--b/c informed by
empirical stuff they have been taught.
-in case of metaphysics--we need to be detached from our sense--seek this truth w/o
sensory input. a priori.
15 -this requires considerable attention on part of reader.
pg. 101 “inattentive and hostile reader”
-commitment to unprejudiced self completely--no bodily influences
how to unprejudice the mind?
-levies an attack on our empirical beliefs
LECTURE OCT 15TH
model of learning is m.:
deductive arguments: ‘duco’ (leave) ‘de’ (from)
foundation of math: begins with axioms: self-evident truths, and premises are added to
eg: axiom of equality
why were deductive args taken to be superior?
if follows rules of logic, and all premises are true, then the answer cannot not be true
-if follows rules of logic then it is true
-therefore, greatest tool in seeking truth
d. (pgs 210, 211, preface to p.o.p.)
-points out this way of reasoning is not exactly what he is looking for: conclusion does
not contain anything new. simply makes the implicit explicit.
d. also has a metaphysical problem with this: in meditations
meditations: seeks out axioms/first principles of all human knowledge.
16 argues that first principles of metaphysics are different (pg 101-104)
pg. 102 and top of 103 “for there is this difference between the two cases...harmonize
with the use of our senses (in m. & geometry)...in the proper deduction of the
consequences...even if you are inattentive...on the contrary, nothing in metaphysics
causes more trouble than making the perception of its primary principles...cannot be
1st principles in g. accord with our senses: no opposition with sense and 1st principles,
therefore self-evidence of g. 1st principles easily grasped by anyone
1st principles of metaphysics d/n agree with use we make of our sense. always a
conflict between 1st principle and our sense. therefore, 1st principle cannot be
apprehended with ease.
therefore, d. proposes:
influence of the senses must be eliminated
person who wants to succeed must be attentive
pg. 101 analysis and synthesis: “Analysis shows the true way...”
-analysis is the method of metaphysics to uncover 1st principles. method of analysis
designed to make us see that they are self-evidently true.
important: the student feels as if he has discovers these truths himself
d. wants to establish g-d as his creator.
-claim is contradicted by the sense: d/n corroborate this claim
-senses would indicate that there is no g-d
-senses unable to establish that g-d is my creator
-therefore, senses must be eliminated to get at metaphysical truth
two different 1st principles:
17 -axiom of equality
-g-d is my creator: connection b/w subj and predicate is not obvious. therefore can be
an act of denial--this is why wants to lead people to self-discovery
1. bodily influence must be eliminated
2. we need to give full attention
3. no hostility
then you will see in your own minds eye the connection between g-d and your creation.
can only be understood through thought (no rhetoric--c/n be persuaded) therefore you
need to come to it as though you yourself had discovered it.
truths discovered in meditations are personal
grasping these truths is not obtained through deduction, but rather through meditation:
the mind thinking on itself, guided by d.
pg. 102, 1st para “synthesis employs an opposite procedure...thus the reader...even if
hostile...compelled to render assent...”
pg 102, 3rd para: “but i have used in the meditations, only analysis”
FIRST MEDITATION: PREAMBLE
goal: seeking 1st principles of hu. kno. --only two possible sources: reason and the
-med. 1 concerned exclusively with sense.
-determination by voyage into skepticism: wether the findings of the senses can
-how do pp who use their senses regard the world, and truth about the world?
-there is a perceiver, and his/her senses. there is the external thing. you must believe
that the thing is in the world. no-one has direct contact with the object itself. the best we
do is have images of objects.
1. (colored glasses change what things look like)--our perception is relative
2. perception always requires a perspective (further away, smaller, vague)
18 3. tools increase/change senses (microscope, telescope)
4. trickery (circus)
perception is representative of reality, it is not that reality itself: representative realism:
the ordinary way of approaching the world. data of sense is unquestionable. perceivers
are never in direct contact with the external world. but we really want to know if
things are really here--we need to know: are my perceptions true of the world?
1. impossible for me to leave my senses to establish truth of sense data (tied to sense).
do my sense-data correspond to reality? (if i see it as blond is it really blond?)
2. correspondence theory of truth (do perceptions correspond to reality?). need to find
a feature in perception that, when present, guarantees that sense datum
correspond to reality.
...soooo...how do we do that?
med. pgs 58, 59 “and the little that i have said...”
-features of clarity and distinctness, mind’s signs of truth
how med. 1 is set up: (preamble cont.)
-principle of evidence: our mind must be operating with principles of evidence
-1st principle of evidence is the lowest, least reflective--will isolate clarity and
distinctness as a feature--will cover a range of perceptions--admitted into
consciousness as true. (perceptions not clear and distinct regarded as false).
-we want indubitably, so if this principle has ever led us to an error in fact or principle
(ie, we might have made a mistake) then we must reject principle of evidence, clarity
and distinctness, and range of perceptions.
2. come up with a second principle of evidence
-one which is more reflective
-will also utilize clarity and distinctness
-will admit a range of perceptions into consciousness
-using this principle, can we still make an error in fact and principle?
19 procedure: dialectic/dialectical: the succeeding principle of evidence improves upon the
first one. built upon the failures of the first one.
3. principle of evidence 3: has notion of clarity and distinctness, admits into c/s a range
of perceptions, we ask if error in fact/principle is possible...end up rejecting everything
Q: what is the last possible notion of clarity, perceptions, etc?
hyperbolic doubt. (most perceptions are probably true)
if_____(sufficient condition) then______(necessary condition--sine que non--without
oxygen a necessary condition of combustion
d. if dubitable, must be rejected
if dubitable, is rejected
if not rejected, is indubitable
-everything not rejected/accepted must be be indubitable
-everything rejected can be dubitable
seeking 1st principles which cannot be doubted
1st med: seeking a principle which is indubitable.
med: pg. 45 & 45 “to build anew from the foundation....i shall only attack those principles
upon which my former beliefs rested...principles are sometimes deceptive”
p1: (most naive) the senses are always clear and distinct. perceptions correspond to
pg. 46: “but it may be that the senses sometimes deceive us...”
20 therefore, d. rejects.
p2: (revised on shortcomings of the first)
*look at: pg 151-152 in CK vol 2 (pg 57 CK)
OCTOBER 22ND LECTURE
text next week: starts at 8:30. just under two hours. author, journal, journal #, and pg
#’s--title, publishing co.
brevity not a virtue. use pen. write clearly.
last wk: preamble. attacking representative realism. the idea that the best we can have
is a perception of the object. how do i know that my perception of the table is an
accurate representation? correspondence theory of truth (hoping perception
corresponds with reality?).
d: we cannot jump out of our skin to look at the table
therefore, we have to establish the correspondence though the representation of the
table. how can you know, by examining perceptions, that there is a correspondence?
we have to find features within perception, which, if present, guarantee that the
perception corresponds with the object: clarity and distinctness.
are any of our perceptions adequate for this job?
med 1: trying to get a clear account of clarity and distinctness
how do you seek clarity and distinctness? d: humans utilize principles of evidence.
21 regulatory principles. through principles of evidence that a set of perceptions is emitted
in order to test a partic princ of evidence--we need to ask if it has ever produced a
mistake. even if it always worked, asks: could there be an error in principle? therefore
reject principle, clarity and distinctness, and perceptions.
it goes beyond logic. it is not logical to reject everything based on one doubt. but the
search for 1st principles requires this approach.
test: principles of evidence which follow the first one are dialectical--each tries to correct
the one previous to it.
clarity and distinctness are redefined: yields another set of perceptions. the cycle
principle of evidence ‘n’--last possible principle of evidence--dfn of clarity and
distinctness, a set of perceptions, and rejects everything.
end of the quest for 1st principles using perception
what is the ‘n’ point?
med pg 49 “But it is not sufficient...doubtful but probable...i allow myself to be
deceived...judgement no longer dominated by bad usage”
the senses are always pushing us into doubt. the hyperbolic doubt works against the
senses. where the influence of the senses and the hyperbolic doubt meet we have
reached a point of indifference. purpose: to yield to indifference. if you are hostile to this
project (pg. 101, 102) it won’t work. starting point of inquiry: no prejudice whatsoever.
pg. 49, last para: the evil genius who deceives me. not g-d. another hypothesis. finite
power. can deceive you as much it wants. the personification of hyperbolic doubt.
22 med. 1
principles of evidence:
pg 45/46 “upheaval of former opinions”
-if you find one mistake--whole thing is out.
-attack principles of evidence upon which my previous kno. hinged.
POE 1(principle of evidence): the senses are always reliable
-is indiscriminate in what it takes to be true.
how does he know he has made mistakes?
-things which are hardly perceptible or very far away
-contradiction in what the senses lead to
POE 2 (principle of evidence)
pg 46 “But it may be that although the senses sometimes deceive me...” ie: the sense
turn out to be reliable when our perceptions are clear (highly perceptible) and distinct
(knowing the components of an object).
one counter-example to this POE: pg. 46, 2nd para, middle: crazy people example...
so...the counter example is madness.
madness: people who create their own reality that have nothing to do with the external
not deception but illusion. loss of contact with reality.
how does descartes know he is not mad? people who are mad are unable to
distinguish reality from illusion. delusion. create own reality, and errors cannot be
mad pp have true perceptions.
need another POE (3): the sense are reliable whenever our perceptions are clear
(highly perceptible) and distinct (components known, and there is no reason to doubt
23 the accuracy of our perceptions)
POE 3: is there any sense in which it is true to say that normal, non-mad people are
delusional? are normal pp delusional? can they tell when they’re not delusional?
pg 46: last para: “I am in the habit of sleeping...in my dreams...”
same content awake and asleep--the content of wakefulness is reproduced in sleep.
there is no way to prove that at any given moment you are awake. cannot prove it.
might be asleep now. it means you, like the mad person, is delusional. even though the
content of the dream is the same as if you are awake.
since have no way to determine waking from sleeping, will assume that i am asleep an