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Epistemology:

Epistemology: The The

philosophical

philosophical examination of

examination of knowledge – its nature

knowledge – its nature

and its origin.

and its origin. Rationalism:

Rationalism: Epistemological school

Epistemological school

that maintains that the

that maintains that the

most important truths

most important truths

about reality are

about reality are obtained by means of

obtained by means of

the intellect (the mind)

the intellect (the mind)

alone, without relying at

alone, without relying at

all upon the senses.

all upon the senses.

Descartes’ WorldDescartes’ World

Descartes lived during the first half of Descartes lived during the first half of the Seventeenth Century (1596 – 1649).the Seventeenth Century (1596 – 1649).

A Revolutionary and Uncertain TimeA Revolutionary and Uncertain Time

CopernicusCopernicus

GalileoGalileo

KeplerKepler

Reformation (1520)Reformation (1520)

Thirty Years War (1619 – 1648)Thirty Years War (1619 – 1648)

Europe’s pop. shrank by 6.5 million Europe’s pop. shrank by 6.5 million during this war.during this war.

Descartes’ MotivationDescartes’ Motivation

Descartes was a mathematical genius. Descartes was a mathematical genius. Developed the Developed the x yx y graphing grid still graphing grid still used today (the Cartesian point used today (the Cartesian point system).system).

Given the times in which he lived and Given the times in which he lived and his temperament, Descartes wanted to his temperament, Descartes wanted to find the same certainty in philosophy find the same certainty in philosophy that he found in mathematics.that he found in mathematics.

Descartes’ Method of Systematic Descartes’ Method of Systematic DoubtDoubt

Descartes resolved to doubt anything Descartes resolved to doubt anything that that couldcould be doubted. be doubted.

He was looking for at least one totally He was looking for at least one totally indubitable, absolutely certain truth indubitable, absolutely certain truth upon which he could build his entire upon which he could build his entire philosophy.philosophy.

He was looking for a philosophical He was looking for a philosophical Archimedean point.Archimedean point.

“ “Archimedes, in order that he might draw Archimedes, in order that he might draw the terrestrial globe out of its place, and the terrestrial globe out of its place, and transport it elsewhere, demanded only that transport it elsewhere, demanded only that one point should be fixed and immoveable; one point should be fixed and immoveable; in the same way, I shall have the right to in the same way, I shall have the right to have high hopes, if I am happy enough to have high hopes, if I am happy enough to discover one thing only which is certain and discover one thing only which is certain and indubitable.”indubitable.”

Rene Descartes, Rene Descartes, Meditations on First Meditations on First PhilosophyPhilosophy

N. B.:N. B.: Descartes engages in Descartes engages in philosophicalphilosophical, , NOT genuineNOT genuine, doubt. , doubt. Despite the hyperbole he sometimes Despite the hyperbole he sometimes employs, Descartes does employs, Descartes does notnot really really doubt the things he says he does; doubt the things he says he does; rather, he rejects as his philosophical rather, he rejects as his philosophical Archimedean point anything that Archimedean point anything that cancan be doubted.be doubted.

What What cancan be doubted? be doubted?

The reports of the senses.The reports of the senses.

Dreams sometimes mistaken for reality.Dreams sometimes mistaken for reality.

““How often has it happened to me How often has it happened to me that in the night I dreamt that I that in the night I dreamt that I [was] in this particular place, that I [was] in this particular place, that I was dressed and seated near the was dressed and seated near the fire, whilst, in reality, I was lying fire, whilst, in reality, I was lying undressed in bed . . . ! [I]n dwelling undressed in bed . . . ! [I]n dwelling carefully on this reflection I see so carefully on this reflection I see so manifestly that there are no certain manifestly that there are no certain indications by which we may clearly indications by which we may clearly distinguish wakefulness from distinguish wakefulness from sleep . . . .”sleep . . . .”

Meditations on First PhilosophyMeditations on First Philosophy

Since in his dreams he’s dreamed that he’s had all Since in his dreams he’s dreamed that he’s had all sorts of strange, grotesque bodies, Descartes sorts of strange, grotesque bodies, Descartes realizes that his belief that he has a body at all realizes that his belief that he has a body at all could be false; so, he will doubt even that.could be false; so, he will doubt even that.

A very powerful, very evil genius (sort of a A very powerful, very evil genius (sort of a super Satan) might be continually deceiving super Satan) might be continually deceiving Descartes even about his mathematical Descartes even about his mathematical beliefs, e.g. 2+2=4; so, he will doubt even beliefs, e.g. 2+2=4; so, he will doubt even these.these.

What canWhat cannotnot be doubted? be doubted?

“ “. . . let him [the evil genius] deceive me as . . . let him [the evil genius] deceive me as much as he will, he can never cause me to much as he will, he can never cause me to be nothing so long as I think that I am be nothing so long as I think that I am something. So that, after having reflected something. So that, after having reflected well . . . we must come to the definitive well . . . we must come to the definitive conclusion that this proposition, conclusion that this proposition, I amI am, I , I exist, is necessarily true each time that . . . I exist, is necessarily true each time that . . . I mentally conceive it.mentally conceive it.

Meditations on First PhilosophyMeditations on First Philosophy

Cogito, ergo, sum.Cogito, ergo, sum. “I think; therefore, I am” “I think; therefore, I am” from Descartes’ from Descartes’ Discourse on MethodDiscourse on Method..

In order for the evil genius to deceive him, In order for the evil genius to deceive him, Descartes must exist because something Descartes must exist because something that does not exist cannot be deceived.that does not exist cannot be deceived.

But, But, whatwhat is Descartes, i.e. what is Descartes, i.e. what typetype of of being is he? being is he?

““I am not more than a thing which thinks, that is I am not more than a thing which thinks, that is to say a mind or a soul, or an understanding, or a to say a mind or a soul, or an understanding, or a reason . . . . I am . . . a real thing and really exist; reason . . . . I am . . . a real thing and really exist; but what thing? I have answered: A thing which but what thing? I have answered: A thing which thinks”thinks”

Meditations on First PhilosophyMeditations on First Philosophy

Descartes has found his philosophical Descartes has found his philosophical Archimedean point – his own existence Archimedean point – his own existence as a mind.as a mind.

Clear and Distinct StandardClear and Distinct Standard

““[Since] there [is] nothing at all in the [Since] there [is] nothing at all in the statement statement ‘I think; therefore, I am’‘I think; therefore, I am’ which assures me of having, thereby, which assures me of having, thereby, made a true assertion, excepting that I made a true assertion, excepting that I see very clearly that to think is see very clearly that to think is necessarily to be, I came to the general necessarily to be, I came to the general conclusion that I might assume, as a conclusion that I might assume, as a general rule, that the things which we general rule, that the things which we conceive very clearly and distinctly are conceive very clearly and distinctly are all true . . . .”all true . . . .”

Meditations on First PhilosophyMeditations on First Philosophy

Descartes will accept as true any idea Descartes will accept as true any idea that he conceives as clearly and that he conceives as clearly and distinctly as the idea that he exists as a distinctly as the idea that he exists as a mind.mind.

The Eidological Proof for GodThe Eidological Proof for God

Descartes has an idea of perfection, i.e. Descartes has an idea of perfection, i.e. of Godof God

God is “infinite, eternal, immutable, God is “infinite, eternal, immutable, independent, all knowing, all powerful, independent, all knowing, all powerful, and [the Being] by Whom I myself and and [the Being] by Whom I myself and everything else . . . have been created.”everything else . . . have been created.”

Meditations on First PhilosophyMeditations on First Philosophy

Descartes clearly and distinctly Descartes clearly and distinctly perceives that the origin of his idea of perceives that the origin of his idea of God can only be God Himself, i.e. the God can only be God Himself, i.e. the only thing that can generate within only thing that can generate within Descartes the Descartes the ideaidea of a perfect being of a perfect being isis a perfect being.a perfect being.

Since, therefore, Descartes possess an Since, therefore, Descartes possess an idea of God, God must, and does, exist.idea of God, God must, and does, exist.

Anticipating an objection Ludwig Feuerbach Anticipating an objection Ludwig Feuerbach would raise 200 years later, Descartes says:would raise 200 years later, Descartes says:

““Nor should I imagine I perceive the Nor should I imagine I perceive the infinite . . . only by the negation of the infinite . . . only by the negation of the finite, just as I perceive repose and finite, just as I perceive repose and darkness by the negation of movement darkness by the negation of movement and light . . . . For, how would it be and light . . . . For, how would it be possible that I should know . . . that possible that I should know . . . that something is lacking [in] me, and that I something is lacking [in] me, and that I am not quite perfect, unless I had within am not quite perfect, unless I had within me some idea of a Being more perfect me some idea of a Being more perfect than myself, in comparison with which I than myself, in comparison with which I should recognize [my] deficiencies.”should recognize [my] deficiencies.”

Meditations on First PhilosophyMeditations on First Philosophy

Descartes’ idea of God cannot be merely a Descartes’ idea of God cannot be merely a projection and magnification of his own projection and magnification of his own nature.nature.

Descartes claims he would not be able to Descartes claims he would not be able to recognize his own imperfections, unless he recognize his own imperfections, unless he had a prior idea of perfection by which to had a prior idea of perfection by which to judge himself deficient.judge himself deficient.

AmadeusAmadeus

The Deduction of MatterThe Deduction of Matter

God has placed in humans the strong God has placed in humans the strong desire to believe in the existence of desire to believe in the existence of material objects they clearly and material objects they clearly and distinctly perceive.distinctly perceive.

If God has placed this desire in humans If God has placed this desire in humans and their clear and distinction and their clear and distinction perceptions are delusory, then God is a perceptions are delusory, then God is a tease and a deceiver.tease and a deceiver.

Since God is perfectly good, He cannot Since God is perfectly good, He cannot be a tease and a deceiver.be a tease and a deceiver.

Thus, humans’ clear and distinct Thus, humans’ clear and distinct perceptions are veridical, and the perceptions are veridical, and the material objects they clearly and material objects they clearly and distinctly perceive really do exist.distinctly perceive really do exist.

Critique of DescartesCritique of Descartes

The Cartesian CircleThe Cartesian Circle

Descartes first appeals to the clear and Descartes first appeals to the clear and distinct standard to prove God, then he distinct standard to prove God, then he appeals to God to prove the clear and appeals to God to prove the clear and distinct standard.distinct standard.

Response:Response: There are There are twotwo clear and distinct clear and distinct standards – one for standards – one for conconceiving and the ceiving and the other for other for perperceiving.ceiving.

Descartes uses the intuition of his mind to Descartes uses the intuition of his mind to establish the first standard, and he makes establish the first standard, and he makes God the guarantor of the second.God the guarantor of the second.

Recognizing imperfectionRecognizing imperfection

Does Descartes really need an idea of Does Descartes really need an idea of perfection to realize he is imperfect?perfection to realize he is imperfect?

No.No.

Wouldn’t, at most, Descartes only need an Wouldn’t, at most, Descartes only need an idea of the better?idea of the better?

Yes.Yes.

Can’t Descartes conceive of the better by Can’t Descartes conceive of the better by magnifying his own qualities?magnifying his own qualities?

Yes.Yes.

If Descartes were to claim that he had an If Descartes were to claim that he had an actual actual experienceexperience of perfection, like of perfection, like Salieri’s experience upon encountering Salieri’s experience upon encountering Mozart’s music, then, perhaps, he could Mozart’s music, then, perhaps, he could argue only a perfect being could cause such argue only a perfect being could cause such an experience.an experience.