Intermed Symbolic Logic
Intermed Symbolic Logic PHI 112
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Transcription and Restricted Quanti ers Differences Among Quanti er Expressions 0 Some English quanti er expressions are neutral with respect to the range of ob7 jects whose quantity they express 7 Any every all whatever 7 some 7 Anything everything 7 something 7 There is at least one is o Other quanti er expressions apply only to a limited range of objects 7 Anyone anybody 7 someone somebody persons 7 Anywhere everywhere 7 somewhere places 7 Whenever always when 7 sometimes times Limiting the Domain 0 One way of transcribing sentences with restricted quanti ers is to limit the do7 main to the objects to which the quanti ers are supposed to apply 7 D x x is a person so Vx and 3x apply only to persons 7 Everybody is happy is transcribed as VxHx where Hx x is happy 0 However this only allows us to talk about items in the domain so that in the last example we could not transcribe Everybody is happy sometimes Restricted Quanti ers 0 One way to transcribe sentences with a mixture of types of quanti er expressions is to create a new kind of quanti er in Predicate Logic the restricted quanti er 0 We choose a predicate letter to symbolize the restricted range of objects 7 P stands for the set of all persons 7 We write Vxp for everyone and Hxp for someone 7 Everyone is happy is transcribed as VxpHx We can mix restricted quanti ers to symbolize sentences containing more than one limited quanti er expression 7 T stands for the set of all times 7 Everyone is happy sometimes is transcribed as Vxp3yTny where ny x is happy at y Semantics for Restricted Quanti ers o Tarski7style semantics can be used to specify satisfaction7conditions for sen7 tences with restricted quanti ers o For each restriction represented by a one7place predicate S we generate the set rS from VS by stripping off the angle brackets 7 LetvP ltAdam ltEvegt rP Adam Eve 0 Then we say that d satis es HusPu if and only if for some object 0 E rS d0u satis es Pu 7 LetvB Adamgt then dAdamx satis es Bx so d satis es 3Xpr 0 Similarly d satis es VusPu if and only if for all objects 0 E rS d0u satis es P u Eliminating Restricted Quanti ers 0 Restricted quanti ers can be eliminated in favor of other constructions without change in truth7value o 3usPu is equivalent to 3uSu amp Pu 7 3x 0 VusPu WK 0 The replacement of one form for the other when authorized may occur in an internal part of a sentence pr is equivalent to 3xPx amp Bx is equivalent to VuSu D Pu pr is equivalent to VxPx D Bx 7 HxpLxe D 3xpLex is equivalent to 3xPx amp Lxe D 3xPx amp Lex Proof of Equivalence for Restricted Existentials o HusPu is true in I if and only if if it is satis ed by all variable assigments d based on I 0 Let I be an arbitrary interpretation and d an arbitrary variable assigment based on I o d satis es HusPu iff some object 0 E rS d0u satis es Pu 0 iff for some object 0 in D d0u satis es Pu and the one7tuple lt0 6 VS by the de nition of rS 0 iff for some object 0 E D d0u satis es Pu and d0u satis es Su Ryle on Systematically Misleading Expresssions G J Mattey Fall 2005 Philosophy 156 OrdinaryLanguage Philosophy 0 Wittgenstein s emphasis on the way language is used in ordinary situations her alded the beginning of a new philosophical movement 0 Ordinarylanguage philosophers try to dissolve philosophical problems by show ing that they are based on some misinterpretation of ordinary language 0 More positively they investigate ordinary language with an eye to discovering important ways in which it works The movement was centered at Oxford University and hence is sometimes known as Oxford philosophy 0 Among the leading practitioners of ordinary language philosophy at Oxford were Gilbert Kyle and J L Austin Systematically Misleading Expressions 0 There are many expressions occurring in ordinary language which have two fea tures They are perfectly well understood by those who use them in a nonphilosophical way Their grammatical form improperly characterizes the facts which they record 0 Such expressions are called misleading because their improper form is not apparent in everyday usage 0 The misleadingness is systematic because all expressions of that grammatical form would be misleading in the same way and for the same reason Philosophical Analysis 0 Philosophical arguments have always largely if not entirely consisted in at tempts to thrash out what it means to say so and so 0 People use expressions in nonphilosophical situations o Philosophers isolate from these a class of certain more or less radical expres sions 0 Then they ask what all expressions of this class really mean 0 To say that they analyze concepts or judgments is itself misleading as will be seen below What the philosopher does is to try to discover the meanings of the general terms of certain sentences A Paradox of Analysis 0 Why must the philosopher even ask what an expression really means 0 If the expression is used intelligibly then there is nothing there to explain In fact the philosopher must already know what it means if he is to analyze it o If the expression is not used intelligibly then there is no reason to suppose they mean anytihng 0 So there is no darkness present and no illumination required or possible Clari cation 0 Perhaps the task of the philosopher is to clarify expressions whose meaning is only confusedly known by those who use them in ordinary communication 0 If there is real confusion about the meaning then the expression is not intelligi ble and it is not the business of philosophers to clarify it o If there is no confusion in meaning there may still be confusion in the con veyance of the meaning 0 But this sort of clari cation is the domain of linguists not philosophers o The expressions philosophers clarify are ones which are wellunderstood by their users but have an inappropriate grammatical form 0 If the grammatical form is taken literally by philosophers they will be plunged into error QuasiOntological Statements 0 The rst class of radical expressions examined by Kyle is labeled quasi ontological o Quasiontological statements have the grammatical form of attributing existence to something but they do not really do so Ryle exists God exists Satan does not exist The grammar of these sentences indicates that it is about a subject Ryle God Satan Who has existence as an attribute 0 Compare Ryle is a man The sentence is about Kyle and it attributes to him the quality being a man The Misleadingness of QuasiOntological Statements 0 Kant observed in 1781 that existence is not a real property of objects Thus he could deny that existence is a perfection undercutting the ontolog ical argument 0 More recently philosophers have observed that the logical subject of some quasi ontological statements is not about a subject of attributes Given the truth of Satan does not exist Satan is not the subject of any attributes o This has come to be known as the problem of negative existentials In Search of a Subject of Attributes o It seems possible to preserve the claim that the logical subject of a sentence is the subject of attributes o The logical subject might be thought to be An idea as With the idea of Satan A subsistent but nonactual entity as With a subsisting but not existing Sa tan Meinong o The problem With such attempts is that they are too liberal The truth of Round squares do not exist would imply either that there is an idea of a round square or that round squares subsist 0 With no other plausible xes at hand the claim that logical subjects are subjects of attributes should be rejected Clari cation of QuasiOntological Statements 0 We need to nd another way of getting at the meaning of quasiontological state ments 0 A clue can be found in the denial of the existence of kinds of things Carnivorous cows do not exist 0 The expression carnivorous cows is the logical subject but it is not used to denote the thing or things of which the predicate is being asserted o A reasonable analysis which does not presuppose the existence of any thing or kind of thing is Nothing is both carnivorous and a cow 0 Using this as a template we get the following analyses For God exists Something and one thing only is omniscient omnipo tent and in nitely good For Satan does not exist Nothing is both devilish and called Satan o In each case some attribute is asserted or denied of an I which is not named in the statement The Trap 0 People who utter statements such as Satan does not exist understand perfectly well what they are asserting 0 But there is a trap in that the grammatical form of the sentence seems to indicate the having or not by a subject of a speci ed status eg existence 0 This is re ected in the use of various locutions British Prime Minister Mr Baldwin is a being and ctional character Mr Pickwick is a nonentity Mr Baldwin is an actual object or entity and Mr Pickwick is an unreal object or entity 0 But as negative existentials show often there is no subject whose existential status is being af rmed or denied 0 The worst offenders are philosophers who make Being or Reality the subject of their propositions or who treat real as a predicate The Diagnosis 0 Ordinary people generally do not fall into the trap 0 And only some unwary philosophers are victims of it 0 Anyone who abstracts and generalizes is vulnerable 0 Such people want to know what different facts of the same type have in com mon 0 To do this they must ilse the common grammatical form of the statements of those facts as handles with which to grasp the common logical form of the facts themselves Capone is not a philosopher denies a character of someone Satan is not a reality appears to deny a character of someone Fictions 0 Another example of the attempt to generalize based on grammatical form is this Mr Baldwin is a statesman af rms a character of someone Pickwick is a ction appears to af rm a character of someone 0 There is nothing in the world of which we can say There is a ction as we can say of Dickens There is a storyteller 0 Instead we clarify the statement Pickwick is a ction roughly as implying Some subject of attributes has the attribute of being called Dickens and being a coiner of false propositions and pseudoproper names QuasiPlatonic Statements 7 o A second class of systematically misleading expressions is that of quasiPlatonic statements or statements seemingly about universals 0 Once again there is a misleading parallelism in grammatical forms Jones gave himself the prize af rms a character of someone Virtue is its own reward appears to af rm a character about a universal 0 But it is absurd to plug the expression allegedly referring to a universal into the subj ectposition of the rst sentence Virtue gave himself the prize 0 Kyle would later call this kind of attribution a category mistake o The correct clarifcation of Virtue is its own reward would be Anyone who is virtuous is bene tted thereby Against Universals 0 Kyle opines that all statements seemingly about universals can be clari ed to show that they are not about universals o If the need for universals is eliminated then general terms need not be taken to stand for them 0 Then questions about what kinds of things iiniversals are such as were asked by Plato turn out to be bogus o Doubly misleading are Platonic and AntiPlatonic assertions which are quasi ontological and quasiPlatonic statements Equality is a real entity 0 Kyle does not commit himself to the elimination of iiniversals in general but only in some cases 0 As before ordinary speakers know what they mean when using quasiPlatonic statements and often their statements are true QuasiDescriptive Phrases o A third class of systematically misleading expressions concerns sentences with the phrases o In many cases these phrases are used referentially as descriptions of a unique individual de nite descriptions The King of England Tommy Jones is not the King of England 0 But in some statements they are used nonreferentially and thus function as quasidescriptions Poincare is not the King of France 0 If the King of France were used referentially there would have to be an entity intended as its denotation but there is none 0 So de nite descriptions are systematically misleading expressions The Meaning of an Expression 0 There are many ways in which quasidescriptions are misleading 0 One particularly important one occurs in the meaning of expression x o It is not intended that there be a meaning in the way that there is a person about whom it is asserted our village policeman is fond of football 0 So there is no need to assert that there are concepts to serve as the meanings of expressions 0 And questions about the character of concepts such as whether they are sub jective or obj ective are not about anything 0 Nonetheless we can intelligibly discourse about meanings of expressions The meaning of z is y can be clari ed as 1 means what y means Occam s Razor 0 A common feature of the types of systematically misleading that have been dis cussed is that they lead to the presumption of the existence of new sorts of ob jects Nonexistent beings Universals Meanings o In each case entities are multiplied needlessly 0 Thus Occam s injunction not to multiply entities without necessity can be under stood in terms of grammatical forms Do not treat all expressions which are grammatically like proper names or referentially used the phrases as if they were therefore proper names or referentially used the phrases Some Puzzles o In what sense are we to say that a grammatical form is proper to a set of facts without lapsing into a Wittgensteinian picture theory or conventionalism o How are we to discover whether particular cases are systematically misleading They lead to paradoxes o How can systematically misleading expressions be exhaustively catalogued 0 Can it be proved that an expression contains no systematic misleadingness at all 0 Does philosophy have a higher calling than merely to detect the sources in lin guistic idoms of recurrent misconsttuctions and absurd theories Philosophy 168 Lectures on Meditation Two G J Mattey April 2 2009 The aim of the Second Meditation M2 as stated in its sub title is two fold 1 to establish the nature of the human mind and 2 to show that the mind is better known than bodies In the Synopsis AT VII 12 CSM II 9 Descartes describes the outcome of M2 somewhat differently First the mind is said to use its own freedom to suppose that everything about which it has the slightest doubt does not exist In the process the mind discovers that it is impossible that it should not exist during this time The exercise of supposing the non existence of that whose existence can be doubted has a side benefit of enabling the mind to distinguish without difficulty what belongs to itself ie to an intellectual nature from what belongs to the body He does not try to prove the immortality of the soul here but he does provide the basis of premises for a proof Now the first and most important prerequisite for knowledge of the immortality of the soul is for us to form a concept of the soul which is as clear as possible and is also quite distinct from every concept of body and this is just what has been done in this section AT VII 13 CSM II 9 In the Second Replies Descartes states that he was not at this point claiming that the mind is distinct from the body but was merely examining those of its properties of which I can have certain and evident knowledge AT VII 129 CSM II 93 He goes on to state that his goal was to show that the mind when taken in isolation from bodily attributes is better known than the body when taken in isolation from the mind The Cogito The first three paragraphs of M2 culminate in one of the most famous claims in the Cartesian philosophy that this proposition I am I exist is necessarily true whenever it is put forward by me or conceived by my mind AT VII 25 CSM II 17 A similar claim had been made earlier in Part Four of the Discourse on Method But immediately I noticed that while I was trying thus to think everything false it was necessary that I who was thinking this was something And observing that this truth I am thinking therefore I exist was so firm and sure that all the most extravagant suppositions of the sceptics were incapable of shaking it I decided that I could accept it without scruple as the first principle of the philosophy I was seeking AT VI 32 CSM I 127 This principle has come to be known as the Cogito after the Latin word which is here translated as I am thinking We will return shortly to the difference between the two formulations of this principle G J Mattey s Lecture Notes on Descartes s Second Meditation 1 In the Fourth Objections AT VII 197 198 CSM II 138 Arnauld notes that St Augustine had already pointed out that it is impossible for one to be mistaken about one s own existence 011 Free Will Book II Chapter 3 Descartes responds by thanking Arnauld for bringing in the authority of St Augustine to support me AT VII 219 CSM II 154 Late in 1640 Descartes wrote letters to Colvius and to Mersenne thanking each of them for bringing to his attention Book XI Chapter 26 of Augustine s City of God He wrote to Colvius that he had examined the passage in the library and I do indeed find that he does use it to prove the certainty of our existence AT III 247 CSMK 159 He describes the inference that one exists from the fact that one is doubting as being one that could have occurred to any writer But I am very glad to find myself in agreement with St Augustine if only to hush the little minds who have tried to find fault with the principle AT 111 248 CSMK 159 We now turn to the narrative of M2 Descartes reiterates that he is searching for what is certain and unshakeable and to this end he has set aside just as if I had found it to be wholly false whatever admits of the slightest doubt AT VII 24 CSM II 16 A possible outcome of this procedure is that the only thing he finds certain is that nothing is certain But if he can find a single item not matter how slight that does not admit doubt I can hope for great things Here Descartes makes the analogy with the boast of Archimedes that if he could find a lever long enough and a place to stand he could move the earth So sometimes the single item Descartes does find is called his Archimedean point This is what will give him the ability to use something like leverage to enable him to recover some of his former beliefs Specifically what Descartes supposes to be true is that past events occurred as they are represented in his memory that he has no senses that there is no body shape extension movement and place the latter of which are what Descartes will claim to be the chief properties of bodies After having suspended his belief in the world of extended things he moves to the question of whether there is a God or whatever I may call him who is the cause of his having his present thoughts He immediately finds grounds for doubting that claim since he may himself be the author of his thoughts But if he is the cause of his thoughts it seems that he is something The problem sticking point is that it does not seem that there is any way that he could be something since he denied that he has a body But then he asks the crucial question why could he not exist without a body and senses He has convinced himself that there is no world of extended thing and so there must be something that has been convinced If I convinced myself of something then I certainly existed AT VII 25 CSM II 17 Descartes has not quite arrived at the Cogito however He must still confront his supposition of the malicious demon Perhaps this deceiver of supreme power and cunning who is deliberately and constantly deceiving him about the existence of the extended world Nonetheless if he is G J Mattey s Lecture Notes on Descartes s Second Meditation 2 deceived then the must exist And let him deceive me as much as he can he will never bring it about that I am nothing so long as I think that I am something AT VII 25 CSM II 17 At this point he announces the Meditations version of the Cogito that this proposition I am I exist is necessarily true whenever it is put forward by me or conceived by my mind AT VII 25 CSM II 17 Note that this is a very narrow claim Descartes might have said that the proposition I exist is necessarily true whenever he is thinking which would be more in line with the formulation of the Discourse But here he draws the most conservative conclusion possible he can be absolutely certain of his own existence when he is thinking about his existence He seems to want to indicate that it is the very process of doubt which leads to knowledge of his own existence so that he might well have inferred I am doubting therefore I exist As noted in the Discourse Descartes had referred to the proposition I am thinking therefore I exist Cogito ergo sum The use of the term therefore indicates that I exist is the conclusion of an inference The inference can be captured in an argument with a single premise 1 I am thinking Premise 2 Therefore I exist Conclusion Note that this argument is not formally valid in the syllogistic logic of Descartes s time To make the argument valid a major premise is needed Such a premise would be a universal proposition whose subject encodes the premise of Descartes s inference and whose predicate contains the conclusion Before turning to the structure of the inference we should note that a question was raised about whether the concepts occurring in the propositions making up the inference are understood In a letter to Descartes Hyperaspistes claimed that before he can know that the proposition I am thinking therefore I exist is true he must be told the meanings of the components of the propositions such as thing exist and thought Descartes responds by saying that we do know what these terms mean and that people need not be told their meanings because it is so self evident that there is nothing which could serve to make it any clearer AT III 247 CSMK 192 This issue will come up again shortly Descartes was aware of the fact that the argument is incomplete from the standpoint of syllogistic logic He recognized that with the required major premise the argument looks like this 1 Whatever is thinking exists Major premise 2 I am thinking Minor premise 3 Therefore I exist Conclusion In the Second Replies Descartes denies that the inference he made is a syllogistic inference that includes the major premise The proposition I am thinking therefore I exist is said there to be G J Mattey s Lecture Notes on Descartes s Second Meditation 3 recognized as something self evident by a simple intuition of the mind AT VII 140 CSM II 100 In the Principles of Philosophy of 1644 Descartes states that I am thinking therefore I exist is the first and most certain of all propositions to occur to anyone who philosophizes in an orderly way AT VIIIA 9 CSM I 196 But in saying this he is not denying that one must first know what thought existence and certainty are Nor is he denying that one must first know that it is impossible that that which thinks should not exist The latter is an alternative form of the major premise He did not list the notions of thought existence and certainty only because these are very simple notions which on their own provide us with no knowledge of anything that exists Given that reference to the knowledge of the major premise occurs after the list of three notions but before the word these it seems that Descartes wanted to hold that the major premise is also a very simple notion which has no existential consequences But that cannot be right because it does have existential consequences namely the consequence that he exists Frans Burman when interviewing Descartes quotes the Second Replies When we become aware that we are thinking beings this is a primary notion which is not derived by means of any syllogism Originally at AT VII 22 CSM ll 15 quoted at AT V 147 CSMK 333 Burman asks whether in fact Descartes had asserted the opposite in the passage from the Principles discussed above Descartes responds by looking at the inference I am thinking therefore I exist in two different ways He states that in the Principles he was making the point that the major premise comes first because implicitly it is always presupposed and prior and that my inference depends on it Here he seems to be making the point that the formal validity of the inference in syllogistic logic depends on the presence of the major premise On the other hand although the major premise can be known before the inference it does not have to be known before the inference is made nor is it the case that I am always expressly and explicitly aware of its priority The reason is that when he attends only to what I experience within myself he finds that he is not paying attention in the same way to the general notion a whatever thinks exists Thus it seems that Descartes is claiming that he can know that his inference is sound without knowing that it is syllogistically valid The reason is that the soundness of the inferences is self evident As Descartes stated in the Second Replies it is the evident nature of the particular proposition concerning himself I am thinking therefore I exist which provides the basis for his knowledge of the proposition that whatever is thinking exists It is in the nature of our mind to construct general propositions on the basis of our knowledge of particular ones AT VII 141 CSM II 100 So he knows first that it is impossible for him to think without existing and then uses that knowledge as the basis for knowing that whatever is thinking exists This is the line which he reiterates in the conversation with Burman As I have explained before we do not G J Mattey s Lecture Notes on Descartes s Second Meditation 4 separate out these general propositions from the particular instances rather it is in the particular instances that we think of them AT V 147 CSMK 333 In the Appendix to the Fifth Objections and Replies Descartes considers a claim made by Gassendi who supposes that knowledge of particular propositions must always be deduced from universal ones following the same order as that of a syllogism in Dialectic AT IXA 205 CSM II 271 This is the basis of an objection that the major premise lWzatever thinks exists is a preconceived opinion and cannot therefore be used in the inference I think therefore I exist Descartes notes that if the major is a preconceived opinion it need not remain one for when we examine it it appears so evident that we cannot but believe it even though this may be the first time in our life that we have thought about it But the greater mistake is that one must know the general proposition in order to know that particular proposition This is simply not how we learn as can be seen from he fact that a child needs examples before being able to understand When equal quantities are taken from equal amounts the remaining amounts will be equa AT IXA 206 CSM II 271 What Descartes is describing here is a form of induction an inference from particular propositions to general ones He does not here describe under what conditions such an inference is justified He apparently believed that when one considers one or more obvious cases of a certain relation e g thinking and existing one is able to recognize that they have full generality There must be some kind of recognition of this sort since inductive inferences based on mere experienced association is dangerous as Hume was to point out in the eighteenth century One might wish to say that Descartes s explicit inference is an enthymeme an argument with and implicit or suppressed premise Although the major premise is not explicitly thought in the making of the inference it is implicitly thought through the recognition of the connection between the single premise and its conclusion Gassendi in the Fifth Objections claims that Descartes could have made the same inference from any one of your other actions since it is known by the natural light that whatever acts exists AT VII 259 CSM II 180 Then the syllogistic form of the inference would contain a further major premise from which the original major follows Whatever acts exists New major premise Thinking is an action New minor premise Therefore whatever is thinking exists Original major premise I am thinking Original minor premise Therefore I exist Conclusion wewwe Descartes responds that only thinking would do in the minor premises of our reconstructed inference Thought is the only action of which I am metaphysically certain The inference I G J Mattey s Lecture Notes on Descartes s Second Meditation 5 am walking therefore I exist does not confer certainty since it is not certain that I have a body On the other hand my thinking that I am walking would be sufficient Hence from the fact that I think I am walking I can very well infer the existence of a mind which has this thought but not the existence of a body that walks AT VII 352 CSM II 244 cf Letter to Reneri for Pollot 1638 AT 11 3738 CSMK 98 What I am The proposition that I exist does not have much meaning until it is understood what the I is Indeed there is danger of going astray in this understanding and going wrong would undermine the value of the knowledge that I exist For example if I my body we could conclude that my body exists which is inconsistent with the supposition that there are no bodies To get a clear understanding of what he is Descartes recapitulates the progression of M1 That is he begins with his preconceived opinions and then strips away all those that are dubious until nothing remains but what is certain and unshakeable AT VII 25 CSM II 17 Descartes s initial conception of himself is that he is a man But he finds this description of himself to be unsatisfactory because man is a universal term which requires a definition in order to be understood To be sure there is available the Aristotelian definition of man as rational animal Rational and animal are also universal terms which demand definition and in fact the process of definition gets harder the further the concept of man is decomposed Descartes declares that he does not have time to waste by looking for definitions So instead of looking for a general term to describe himself he turns to particular parts properties activities etc that naturally and spontaneously occur to him to apply to himself It appears that at least some of these features of himself are in reality what was taught to him as the features of the soul re ect the Aristotelian account of it o I have a body 0 My body is composed of parts such as a face hands arms 0 My body is a mechanical structure 0 I have a soul 0 My soul nourishes me Aristotelian nutritive or vegetative soul living things 0 My soul enables me to move about Aristotelian sensitive soul animals My soul engages in sense perception Aristotelian sensitive soul animals My soul engages in thinking Aristotelian rational soul humans This list will be pared down to the point that his conception of himself is that of a soul which thinks The two main theses to be rejected are those of materialism according to which the soul is nothing more than the body and Aristotelianism which divides the soul into a hierarchy based on functions some of which nourishment self motion and sense perception are bodily G J Mattey s Lecture Notes on Descartes s Second Meditation 6 The nature of the soul as opposed to what the soul does is something he has either not thought about or else imagined to be something like a wind or fire or ether which permeated my more solid parts AT VII 26 CSM II 17 The nature of the body on the other hand he thinks he knows distinctly A body has a determinable shape A body has a definable location A body can occupy a space in such a way as to exclude other bodies A body can be perceived by the senses A body can move around by bodies that come into contact with it but not by itself The claim that bodies are not self moving is based on Descartes s thought that the power of self movement like the power of sensation or of thought was quite foreign to the nature of a body AT VII 26 CSM II 17 He notes that it found it a source of wonder that certain bodies were found to contain faculties of this kind ie bodies can move themselves sense and think Given the ongoing supposition of the existence of an evil deceiver who has brought it about that he has no body Descartes cannot assert that he has either of the first two features of the soul nourishment and motion Sense perception requires a body Further since we have perceptions when we dream which are indistinguishable from the perceptions we would have by way of the body it seems that a body is not needed for sense perception So it is possible that I exist without having bodily sense perception But thinking is something that is inseparable from me and alone is so inseparable Note that the conclusion that body alone is inseparable from him may be too strong since he will later declare that he does not know whether he is identical to a body He should have stated instead that thinking is the only thing he knows to be inseparable from him This point will be discussed shortly Here it seems that Descartes has in mind the proposition I am thinking therefore I am According to this proposition merely thinking is sufficient for his existence though it does not establish that thinking is necessary for his existence or that he is exclusively a thinking thing Descartes considers the possibility that thinking is a necessary condition of his existence as he notes that it could be that were I totally to cease from thinking I should totally cease to exist AT VII 27 CSM II 18 He does not pursue the matter here as he is only allowing himself to admit what is necessarily true He then draws one of his main conclusions I am then in the strict sense only a thing that thinks that is I am a mind or intelligence or intellect or reason AT VII 27 CSM II 18 The wording of the conclusion naturally suggests that he is exclusively or nothing more than a G J Mattey s Lecture Notes on Descartes s Second Meditation 7 thing which thinks which would preclude his being a thing that moves is nourished etc Gassendi inquired as to what the term only means in this context Does it not have a restrictive force limiting you only to a thing that thinks and excluding other things such as a structure of limbs a thin vapor etc Appendix to Fifth Objections and Replies AT IXa 214 15 CSM II 276 Descartes responds by claiming that the word only modifies strict sense rather than I am Thus I am in the strict sense only a thinking thing He states that a few lines down he showed that by his statement in M2 I do not at all mean an entire exclusion or negation but only an abstraction from material things AT IXA 215 CSM II 276 Specifically Descartes goes on to ask And yet may it not perhaps be the case that these very things which I am supposing to be nothing because they are unknown to me are in reality identical with the I of which I am aware I do not know AT VII 27 CSM II 18 He says that Gassendi has been unfair to him by reading the original passage in such a way that it looks like he is contradicting himself by stating that he is only a thing that thinks but does not know whether he is only a thing that thinks Descartes summarizes is findings by stating that he is a thing that exists and when asked what kind of thing he replies that he is a thinking thing res cogitans After stating that he is a thinking thing Descartes goes on use his imagination to think of what else he is besides being a thinking thing And as we have seen he professes not to know at this point whether he is anything else but a thinking thing The appeal to the imagination here as opposed to his earlier appeal to his preconceived opinions seems to be an attempt to undermine the claims of the materialists who identify the self with the body or something bodily This use of the imagination in fact shows him what he is not Q A structure of limbs called a human body 0 A thin vapor that permeates the limbs The reason for rejecting these materialist identifications of himself with his body or something bodily is that he can conceive himself as existing while supposing that bodies do not exist The key claim is that in understanding the I as he puts it strictly it is quite certain that knowledge of the I does not depend on things of whose existence I am as yet unaware so it cannot depend on any of the things which I invent in my imagination AT VII 27 28 CSM II 18 19 In this sentence the word it must refer back to knowledge so the claim would be that knowledge of the I does not depend on anything dependent on the imagination Imagining is the contemplation of the shape or image of a corporeal thing But corporeal things have been supposed not to exist because the images could merely been the product of dreams Use of the imagination to gain knowledge of the I is futile as it is inferior to the intellect Using the imagination rather than the intellect is like falling asleep in order to represent things more clearly So to perceive the nature of his mind as distinctly as possible he must G J Mattey s Lecture Notes on Descartes s Second Meditation 8 divert his mind from things as presented by his imagination AT VII 28 CSM H 19 Now that we have seen the argument for the claim that the I is not known to be a body and is not known through the senses or imagination we will turn to his critics objections against his arguments and their conclusions Gassendi s charge that Descartes was claiming that he is not a body was first made by Mersenne in the Second Objections You say I am a thinking thing but how do you know that you are not corporeal motion or a body which is in motion AT VII 123 CSM H 88 Mersenne correctly notes that this conclusion does not follow from the supposition that the images of all bodies are delusive Descartes points out in response that he has already expressed his own skepticism when he asks whether the things he has supposed to be nothing are in reality identical with the l of which I am aware AT VII 129 CSM H 93 But this does not preclude him from knowing later that they are not The point of the exercise in M2 was to separate out notions of the mind that had been mixed up The main goal is to show that the ideas of mind and body are distinct In M6 Descartes will argue that if the ideas of mind and body are distinct the things are distinct as well The reason people think that they need their bodies to think is that they have never been without bodies and in fact have been obstructed by them in their thinking The Third Objections made by Hobbes contain the same charge Hobbes questions the inference he attributes to Descartes I am using my intellect hence I am an intellect Hobbes here makes his famous comparison I am walking hence I am a walk Descartes is identifying himself with an intellect but intellect is only a power of a subject Yet all philosophers make a distinction between a subject and its faculties and acts AT VII 172 CSM H 122 So the subject may be corporeal while intellection is a power of the corporeal subject The contrary is assumed not proved Descartes responds that mind intelligence intellect and reason are all things which are endowed with the faculty of thought Mind and intelligence are commonly thought of in this way by everyone lntellect and reason are often thought of in this sense AT VII 174 CSM H 123 The analogy with a walk is fallacious since a walk is commonly understood as an act while thought is sometimes understood as an act sometimes as a faculty and sometimes as the subject of a faculty The major difference between himself and Hobbes according to Descartes is that he Descartes tries isolate concepts to the greatest possible extent in order to avoid confusion whereas Hobbes lumps them together to gain favor for materialism Hobbes goes on to claim that because a thinking requires a thinker and other such dependencies that hold a thinking thing must be corporeal because all subjects are corporeal This seems to G J Mattey s Lecture Notes on Descartes s Second Meditation 9 be based on the assumption that only matter can serve as a subject The claim that it follows from the fact that all acts of thinking have a subject that the subject must be material is made quite without any reason and in violation of all usage and all logic AT VII 175 CSM II 123 4 Descartes is willing to concede grudgingly that the subject may be called metaphysical matter but this does not make it corporeal matter Descartes ends his reply to Hobbes by noting that acts of thought have nothing in common with acts of bodies and that thoughts are different in kind from extension If this is granted it is easy to establish as in M6 that the substances which think and those which are extended are distinct One interesting claim made by Descartes in the heat of battle is that it is certain that in general no act or accident can exist without a substance for it to belong to AT VII 175 6 CSM II 124 Thus there can be no thinking without a thinker no figure without a body This point becomes important in the dispute about transubstantiation The prevailing doctrine was that the accidents that had belonged to bread become unattached to any substance once the bread is changed into the body of Christ The Fourth Objections lodged by Arnauld follow in the same vein He too thinks that Descartes has tried to establish in M2 that I am not a body AT VII 198 CSM II 139 The argument is that while I can doubt that I have a body I cannot doubt that I exist as long as I am thinking Arnauld is sensitive to the fact that Descartes has expressed skepticism about what the I is citing the same passage as Descartes himself cited He then goes on to criticize the argument of M6 The responses are based on the arguments of M6 so they will be passed over here In the Fifth Objections by Gassendi a real battle begins Gassendi notes that the point at which all the hard work begins is to understand what the I is The method of beginning with what he previously thought himself to be is endorsed by Gassendi But Descartes proceeds by regarding himself as a soul not as a whole man but as an inner or hidden component AT VII 260 CSM II 181 At this point he begins to address Descartes as Soul He then asks as series of questions as to why soul could not be corporeal Descartes protests that Gassendi is not taking his method seriously He gets into the game by addressing Gassendi as Flesh because his objections originate not in the mind of a subtle philosopher but came from the esh alone AT VII 352 CSM II 244 Descartes claims that he has corrected the common view whereby that which thinks is supposed to be like wind or a similar body He has done so by showing that while it can be supposed that there are no bodies it cannot be supposed that there is that which enables me to recognize myself as a thinking thing AT VII 353 He has given reasons to assert that I in so far as I know myself am nothing other than a thinking thing This is all that I asserted in the Second Meditation AT VII 355 CSM II 245 G J Mattey s Lecture Notes on Descartes s Second Meditation 10 The replies to the Sixth Objections contain a distinction between the unity of nature and unity of composition The unity of nature comes to this the same substance which can have a shape can move The same thing that understands also wills But there is no such unity of nature between esh and bone And none between thought and extension There is only unity of composition The notion that mind and body are united in a single being is made explicit in M6 Next Descartes asks what a res cogitans or thing which thinks is He responds by providing the following list here followed by examples that seem to be intended by Descartes I doubt a process in which I am presently engaged I understand e g that I am a thinking thing I affirm that I am a thinking thing I deny everything that is uncertain I am willing to uncover new knowledge I am unwilling to be deceived I imagine many things I have sensory perceptions which seem to come from the senses Even if I am asleep all the time and am the victim of deception by my creator whomever that might be these facts hold of me None of these facts is distinct from my thinking or from myself In generating this list Descartes cleverly trades on the process of doubt itself If I am doubting and doing all the other things ancillary to doubting then I exist All these things fall under the general heading of thinking so the general form of inference I am thinking therefore I exist remains correct Further none of these activities make any reference to the body Descartes clearly intended to overthrow the Aristotelian and materialist conceptions of the human being as being in some way essentially physical But what shall I now say that I am when I am supposing that there is some supremely powerful deceiver who is deliberately trying to trick me in every way he can Can I now assert that I possess even the most insignificant of all the attributes which I have just said belong to the nature of body AT VII 26 CSM II 18 Still Descartes had to deal with two aspects of the I which seem to involve the body These are acts of sensing and of imagining Neither is required for the method of doubt to proceed so he cannot establish that the I is a sensing and imagining thing in the same way he establishes that the I is a willing thing etc His only recourse is to appeal to phenomenology or the way things appear to his mind He must appeal to the brute fact that he has images and that there is therefore the power of imagination This power must exist in order to account for my having images and is claimed to be part of my thinking G J Mattey s Lecture Notes on Descartes s Second Meditation 11 The basis for the latter claim is not clear Why might the power of imagination not be purely bodily The same treatment is given to sense perception It is a phenomenological fact that I am now seeing light hearing a noise feeling heat AT VII 29 CSM II 19 Even if I am asleep it remains thatI seem to perceive this things Thus Descartes concludes sense perception as such is merely seeming to perceive What is called sensory perception is strictly just this and in this restricted sense of the term it is simply thinking AT VII 29 CSM II 19 One must ask again what it is exactly that makes this thinking Imagining and sensing seem to be poor relations to the other forms of thinking because they at least simulate bodily processes and because their existence cannot be discovered using the intellect alone It is not made clear whether the I could exist without having these two powers The ultimate conclusion Descartes wants to draw in M6 is that the mind exists separately from the body while at the same time being united to it in such a way as to make up a single thing The first step in prying them apart is to note the distinction in certainty between beliefs about my thinking self and beliefs about my body Here is where the supposition of the demon comes into play I can know a number of things about myself even under the supposition that I have no body This conclusion is purely epistemological that is a conclusion about what can be known better than what Gassendi presses against Descartes the point that some of the activities of thinking seem to have bodily components particularly sensory perceptions He asks whether Descartes believed that the kind of sense perception he classifies a thinking is what completes what is begun by a bodily faculty which resides in the eyes ears and other organs that receives the forms of sensible things AT VII 268 CSM II 187 He asks whether this is the reason Descartes classifies sensory perception and imagination as kinds of thought But if completion of the actions of a bodily sensory faculty constitutes thought then because brutes non human animals have sensory perception it would seem that he would have to allow that they think as well something Descartes is unwilling to concede Gassendi goes on to contest Descartes s view on the point of whether non human animals think Descartes responds by saying that the a priori investigations of the Meditations are not the place to discuss the question of whether brutes have minds which is something that must be investigated a posteriori by observing their behavior He then goes on to claim that he has in fact given a criterion to establish that the mind is different from the body namely that the whole nature of the mind consist in the fact that it thinks while the whole nature of body consists in its being an extended thing and there is absolutely nothing in common between thought and extension AT VII 358 CSM II 248 This criterion is not given in M2 however Descartes also claims that he has distinctly shown on many occasions that the mind can operate independently of the brain AT VII 358 CSM II 248 For example although in sleep the mind has images to be aware that we are dreaming we need only the intellect AT VII 359 CSM II 248 G J Mattey s Lecture Notes on Descartes s Second Meditation 12 The Second Objections contains the criticism that Descartes has not excluded the possibility that thinking is a bodily activity How do you demonstrate that a body is incapable of thinking or that corporeal motions are not in fact thought AT VII 123 CSM II 88 Descartes replies that he is not yet concerned with the nature of thinking itself This will be taken up in M6 Here he notes that people think there is a necessary connection between mind and body because they only experience mind with body and body in uences their thinking But always being associated with a body does not prove that there is a necessary connection between the two It is just as if someone had had his legs permanently shackled from infancy he would think the shackles were part of his body and that he needed them for walking AT VII 133 CSM II 96 His only point in M2 was to show as the sub title of M2 puts it that he knows his mind better than his body Gassendi disputes Descartes s use of the term mind rather than soul to describe himself His problem is that he thought that he was addressing in his objections a human soul or the internal principle by which a a man lives has sensations moves around and understands AT VII 263 CSM II 183 Instead he finds himself addressing a mind alone which has divested itself not just of the body but also of the very soul AT VII 263 CSM II 183 However Gassendi is willing to concede that Descartes means by mind only the function of the soul which enables us to think Descartes responds that people have become accustomed to use the word soul to encompass both the principle by which we are nourished and grow and accomplish without thought all the other operations which we have in common with the brutes and the principle by virtue of which we think AT VII 365 CSM II 252 The element that thinks is subsequently called mind and it is believed to be the principal part of the soul Because Descartes believes that what performs the bodily function is different in kind from what makes us think he has reserved mind for the latter function which he describes in scholastic terms as the first actuality or principal form of man AT VII 356 CSM II 246 The mind is the thinking soul in its entirety not simply one part of the soul Superiority of the Intellect The final part of Meditation Two is devoted to establishing the claim that The puzzling 39I39 that cannot be pictured in my imagination is better known than corporeal things of which one has images in thought This is the reverse of the standard view which is based on giving the lesser known images priority over the better known self Descartes engages in a thought experiment to show that his view is superior to the standard view In this experiment he gives the imagination free reign though only to show that it cannot get very far and should be curbed in the future Rather than focus on general perceptions of bodies in general Descartes will focus on a particular body a piece of wax The reason he considers the particular body is that general perceptions are apt to be somewhat more confused AT VII 30 CSM II 20 G J Mattey s Lecture Notes on Descartes s Second Meditation 13 Descartes enumerates some of the properties of the wax that it has just been taken from the hive that it still has some of its taste and scent that it is hard and cold and when rapped it makes a sound In short it has everything which appears necessary to enable a body to be known as distinctly as possible AT VII 30 CSM II 20 But when placed by the fire all these characteristics vanish while the same wax remains Descartes concludes that because one can identify the same wax through all these changes there must be something other than the sensible characteristics just listed that allows us to understand the wax with such distinctness AT VII 30 CSM II 20 Now the thought occurs to him that something other than the sweetness fragrance color shape sound which make up the wax Instead the wax is a body which presented itself to me in these various forms a little while ago but which now exhibits different ones AT VII 30 CSM II 20 Then the question becomes what is this body which exhibits the various forms If we take away everything which does not belong to the wax we are left with something 0 Extended 0 Flexible Q Changeable Now the question turns to how these characteristics of the wax are represented by the mind It is not by the imagination but a purely mental scrutiny which is now clear and distinct that reveals these characteristics to him It is not the imagination because that power is too limited to be able to picture all the countless possible ways in which the wax can be extended exible and changeable For example how big can it get if more and more heat is applied to it Descartes concludes that the nature of the wax is known by the mind alone ie by the understanding or intellect AT VII 31 CSM II 21 If the question is about the characteristics of wax in general rather than this particular piece of wax then the point is even clearer since the imagination cannot depict generalities but only particulars The wax that the mind perceives alone is the same wax that is perceived by sense or imagination But the point is that the perception of the wax is of purely mental scrutiny and not of imagining or perceiving AT VII 31 CSM II 21 This mental scrutiny maybe initially obscure but it can become distinct if I concentrate on it carefully Although we initially think otherwise one does not see the wax itself when one sees its properties any more than one sees a man himself when he sees a cloaked figure moving down the street The intellect takes off the hat and coat and inspects the man naked so to speak This leads to a dispute with Gassendi who asks if you strip off everything the imagination provides what do you have left We may think that something remains when the accidents are removed the substance or nature of the wax but this is something that always eludes us and it is only a kind of conjecture that leads us to think that there must be something underneath the accidents AT VII 271 CSM II 189 We get no insight into the substance of the wax by the intellect So G J Mattey s Lecture Notes on Descartes s Second Meditation 14 the analogy with the man beneath the clothes is not appropriate Descartes properly responds that he has not really stripped the accidents off from the wax but rather has understood how the substance of the wax is revealed by means of its accidents and how a re ective and distinct perception differs from the ordinary confused perceptions AT VII 359 CSM II 248 A further objection by Gassendi is that every conception of the wax involves having some kind of shape some sort of color AT VII 272 CSM II 190 These determinate characteristics of the wax seem to require that the understanding be some kind of imagination This objection is not directly answered by Descartes The analysis of our knowledge of the wax leads Descartes to conclude that the mind is better known than the body The awareness of the mind itself is truer more certain more distinct more evident than the awareness of the body This claim is based on three reasons Every act of examining the wax implies my own existence The process of examining the nature of the wax reveals the nature of my own mind even more distinctly 3 The mind has great resources for determining its own nature distinctly and any contribution of the body would be insignificant N The question that prompted the examination of the wax was whether bodies whose images appear to be the most distinct conceptions in our minds are known better than my own self AT VII 29 CSM ll 20 The results up to that point had established this conclusion already but the wax case is supposed to nail it down The result of the investigation is that bodies are strictly perceived through the intellect alone by being understood by the intellect The result of the use of the senses or the faculty of the imagination is not strictly perception of the wax And even when we understand them by the intellect we still thereby understand the intellect itself better Hobbes objects that everyone recognizes that knowledge by reasoning is superior to perception by the senses But reasoning is only about names not the nature of things and names are conventional In fact it seems that names arise from the imagination which shows its priority within the mind AT VII 178 CSM 11 1256 Descartes at out denies this Reasoning is linking of the things that are signified by names This explains how people using different languages can reason about the same things Further if names are purely conventional then what Hobbes is asserting could mean anything G J Mattey s Lecture Notes on Descartes s Second Meditation 15 Note on citations Citations from Descartes are given first With the volume and page from the Adam and Tannery edition of Descartes s works aimres Which are given in the margins of the Cottingham Stoothoff and Murdoch translations The Philosophical Writings of Descartes The citation CSM With volume and page numbers are to Volumes I and II of that work While CSMK refers to volume 111 translated by Cottingham Stoothoff Murdoch and Kenny G J Mattey s Lecture Notes on Descartes s Second Meditation 16
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