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Unformatted text preview: Announcements and Such Two Songs -- Blues Traveler (self-titled 1st album) "But Anyway" and "Dropping Some NYC" No Lecture On Tuesday (2/20) First Essays Due Next Tuesday (2/20) late papers: Policy on a letter gradeEach late day counts down a third of (A+ A, A A, etc.) Today: Reason (III of III) Strengths and weaknesses of the classical view Summary of concepts/distinctions on "Reason" Turn-in your papers to your GSI's mailbox in 301 Moses by 4pm Tuesday Some Difficulties and Strengths of the Classical View I Vagueness Many sentences&such as (e.g.) "the painting contains a red orange patch" are vague that it is difficult to tell What this means isthe sentence expresses which proposition because some of their terms are vague a We may thus be unsure whether orgiven patch falls under the term "red" "orange" this does not the concepts But,propositions inimply thatare vague or the question deny there are synthetic a priori truths. the sentence either expresses a Classicist: truth or not. This isn't a reason to necessary classicist just needs one example here: The"no geometric object is a round square" try Some Difficulties and Strengths of the Classical View II Meaning Change and Falsification I Some Difficulties and Strengths of the Classical View II Meaning Change and Falsification II Another potential problem for the classicist is that of meaning change. The terms we usage of "vixen" may change Over time, thethat it becomes difficult to in such a way use can gradually change in meaning. say whether it expresses our concept vixen changed several times in scientific history 1. Scientists discover (despite appearances) that vixens have such significant male characteristics, they are not really female. 2. Scientists discover startling things about vixens, and they come to use "vixen" in a new sense. While they deny that "vixens" in this new sense are always female, what they are thereby saying provides no reason to doubt that what we now mean by "All vixens are female" is true. This sort of thing happens in science a lot. Consider the term "mass". Its meaning has difficult to say which This makes itare expressed (at various times propositions insist The classicist will changeon distinguishing cases of meaning vs falsification. in history) by sentences containing "mass" a Foran classicist, (1) amounts to a falsification of a priori truth, which is impossible. (2) is a mere case of meaning change, But, it does not threaten classicism. and Some Difficulties and Strengths of the Classical View II Meaning Change and Falsification III Some Difficulties and Strengths of the Classical View III The Possibility of Empirical Necessary Truths I take (2) to be possible, and Classiciststhat all cases that appear to they will claim be Other philosophers (e.g., Quine) think that the difference is not clear, and that future some truths of It seems clear that there areanalytic claims) reason (e.g., logical & other real controversy The synthetic a priori is whether there are any truths; and, if there are any, whether they are necessary truths. discoveries can weigh against what the classical view calls analytic propositions. cases like (1) are actually cases like (2). Classicistsaare committed to: all necessary truths are priori. This is worrisome. of necessary truths There seem to be casesthus a posteriori. that are empirical, and It seems we can know the truth -- if not the status -- of such claims intuitively. Audi discusses several examples, including: (1) Water is soluble. (2) Gold is malleable. (3) Water is H2O. seems necessary -- in sense. Eachall are clearly empiricalsomeposteriori. But, &a (1) is necessary in a One could argue that (2) & (3) are trickier. merely nomic sense. Some Difficulties and Strengths of the Classical View III The Possibility of Empirical Necessary Truths II Some Difficulties and Strengths of the Classical View III Essential vs Necessary Truths I conceivable that there could be Is it evengold that is not malleable? This a piece of to see any sense in It seems even harder water that is not H2O. which there could be of were Even if the lawshownaturewould different, it's hard to see that undermine the classicist can maintain that Of course,not analytic. But, the challenge these are here is to the claim: necessary a priori. are other examples that seem even Therethreatening to this tenuous thesis. more the truth of identity claims such as (3). seems more difficult to imagine than ~(1). essentialism is the view Origin(actual) person could notthat (e.g.) a given have had So, consider the following specific claim: Branden's parents are Michael and Gloria. According to origin essentialism (a very widely held view), this claim is absolutely of course, this claim is empirical, and, But, result, it cannot be known a priori. as a necessary -- not even conceivably false. different than other necessary This claim is seen. It's singular & existential. truths we've different parents than they actually have. Distinction: necessary vs essential truths. Some Difficulties and Strengths of the Classical View III Essential vs Necessary Truths II Some Difficulties and Strengths of the Classical View III Essential vs Necessary Truths III An essential truth is a truth about a particular thing, which articulates a essential truths not true As such, worlds, but onlyareworlds inin all possible in which property that is essential to that thing. the particular object in question exists. The Classicist can distinguish necessary truths about necessary existents (numbers, The nature of contingently existing things must be discovered by scientific inquiry nature of necessarily existing The be discovered by reason alone things can amounts to a revision In any case, thisthe naive Classical viewor qualification of the Classical claim necessary a priori etc.) vs contingently existing things (water) Another example (due to Kripke): Hesperus = Phosphorus of as an essential This can be thought is self-identical). truth about Venus (that it worlds where there is no water. this One problem with H20"Classical reply is that it seems "water is is true even in There are further reasons to worry about "Deep" mathematical theorems seem to be marginally a priori (at best), but necessary Some Difficulties and Strengths of the Classical View III Essential vs Necessary Truths IV Consider Goldbach's Conjecture: Every n > 2 is the sum of three primes. is a simple, but Thisnatural numbers."deep" question about the It remains open. I 18 Sources of justification, knowledge and truth ," So, there are necessary truths knowable only through empirical investigation or arduous proof that isn't strictly a priori The classical view: A priori propositions Some Difficulties and Strengths of the Classical View III Essential vs Necessary Truths V Reason 119 between two kinds of necessary truth, those applicable to entmes that must exist, such as (arguably) numbers, and those applicable to entities that need not exist, and second, to argue that the former truths are a priori. The idea might be that necessary truths are grounded in the nature of things, and that the nature of the kinds of things that must exist is Let's suppose it's true (hence, a theorem). of water must be discovknowable through the use of reason. The nature ered by scientific inquiry; that of the abstract properry of roundness is apparent to adequate reflection. It's clearly a (conceptually) necessary truth. .The idea that necessary truths are grounded in the nature of (the relevant) things has some plausibiliry. At best, however, it does not in any obvious Is it a priori? This seems like a stretch. way apply to purely formal necessary truths, such as that if some As are Bs, then some Bs are As, where 'A' have Its proof (let's safelyinassume) will and 'B' are variables and do not stand for anything particular. required so much "technology" that it's to extending the idea to imply i.s, moreover, a further objection the. of it of genuinely A theorem difficult to think apnontyasall necessary truths.a priorimight follow from a necessarily true proposition and thereby be a necessary truth - since what follows from a priori, but knowing It may be "ultimately" anecessary truth is itself necessarily true - yet not be a priori is no way it seems to require more through to know itreason" its entailment by than "pure simply through adequately underIt or adequately understanding self-evident steps from something that is self-evident. We must not simply every such theorem is self-evidently entailed by a self-evident Necessary propositions analytic a priori synthetic a priori The revised view: Necessary propositions analytic a priori A priori propositions SynthetIc propositions { { 1 synthetic a priori 1----------synthetic empirical Figure 4.1 The a priori, rhe analytic, and the necessary Some Difficulties and Strengths of the Classical View IV Reason, Experience, and A Priori Justification Some Difficulties and Strengths of the Classical View V A Priori Beliefs the shortcomings Despite remains attractive of the Classical View, it in many ways. reason is a powerful and It suggests thatfor belief and knowledge. active capacity justification Principle of one believes afor a priori belief. Normally, if proposition of knowledge a priori PrincipleNormally, if onefor correcttrue beliefs. believes a solely on the basis of (adequately) understanding it, this belief is justified. In this sense, reason is analogous to introspection (as opposed to perception). to deny the genetic dependence This is noton experience. We need of reason once we have the concepts, But,powerfully, independently of reason can act experience. experience to acquire concepts, etc. One can, virtually at will, use reason to arrive at many justified beliefs and much knowledge (albeit only a priori knowledge) Principle? Normally, if one believes a or proposition solely on the basis of one proposition in the a priori way described above, then one knows that it is true. That is: Normally self-evident entailment transmits this kind of a priori justification. more premises that self-evidently entail it and are themselves believed in the a priori way just described, this belief is justified. Some Difficulties and Strengths of the Classical View VI Loose & Strict "A Priori Justification/Knowledge" I Some Difficulties and Strengths of the Classical View VI Loose & Strict "A Priori Justification/Knowledge" II there are beliefs Just asperceptiblenon-perceptual are non-a about objects, there may learn even a self-evident Itestimony. This is a testimonialtruth p via belief a belief may priori justified" in Also, sense, even ifbe "anot strictly a priori. a loose it's believe mathematical theorem on the Ibasis of aa very subtly, and reasonably, incorrect understanding of it. about an a priori p, not an a priori belief priori beliefs about a priori propositions "deep" mathematical With believe p on the basis theorems p, I may of self-evident won't be a priori in While thissense (since "deep"knowledge are the strict theorems axioms, together with a justified true belief of an entailment of p by the axioms. not strictly a priori), it may be "loose" APK. Two kinds of (strict) a priori justification: Justification based directly on the p understanding of a self-evident claim call these cases of a priori We don't want to perhaps there could be a knowledge. But, "loose" sense of APK, based on "loose" APJ. Justification based indirectly on the a understanding of q, via understanding self-evident entailment of q from a selfevident p. [inferential a priori justification] Reaso 124 Sources of justification,knowledge and truth KNOWLEDGE: justification (even in the strict sense) should be considered indefeasible. Perhaps, moreover, notsense: knowledge (a) of a proposition justificatio A priori in the loose all presumptively indefeasible Some Difficulties strict sense) should be considered VII that justification a priori.notthe and my justification forbut is provable indefeasible. prop in ConsiderorStrengths of the Classical Viewby I exist, a Some Difficulties and Strengths logical truths View VI Justification for believing even certain of the Classical can be defeated by be (even is Summarizing the Distinctions II directly indirectly self-evident believing that Summarizing the Distinctions I Justification for believinga even certain necessarytruths is arguably such by I self-evidentpriorifrom some self-evident proposition, and steps nor logical that is neither but can be defeated that plausible skeptical arguments. plausible skeptical (b) constituted it. a priori belief: arguments. Several kinds by belief based on understanding such a proof. unjustifiably believeof If there is indefeasible justification, this is im We've seen a large number of distinctions. in dealing with skepticism (as Chapter 10 will), but plainly such ju First, several kinds of a priori propositions: A a characteristic sense: (a) held in a a priori or empirical tion is not priori in the narrow mark of either an priori way; roughly, justif on an understanding (possibly an inadequate understanding) If, on thebased proposition in question, indefeasible justification (something other hand, there is no A priori in the narrow sense: self-evident; roughly, of priori in the narrow sense: and (b) of a proposition that is a priori the A adequate understanding and truth . open here), the least ourbroad sense). self-evident; roughly, 124 Sources of justification,knowledge is a sufficient ground for (in at narrow or understanding of simple self-evident truths o adequate understanding is a sufficient ground for . BELIEF: justification; belief based on such understanding constitutes gives us justification; belief based on such understanding constitutes truths and both very secure justification for believing those justification (even knowledge.strict basic case is direct be considered indefeasible. in the (This sense) should self-evidence.) presumptively indefeasible them, knowledge. (This the case we doPerhaps, them on basic basisisofheld in an a priori way but believe moreover, not all direct self-evidence.) adequately understanding justif A priori in the broad sense: (a) Justification for believing even certain logical truths can be defeated by be a them. Consider my justification for believing that I exist, a edge of priori.an empirical proposition. PROPOSITIONS: (b) of 124 Sources of justification,knowledge and truth ---- plausible skeptical A priori in the broad sense: not directly self-evident but either arguments. (a)indirectly self-evident, l.e., not self-evident but self-evidently entailed by a self-evident proposition, or (b) ultimately a priori, i.e., not-selt-evldsnt in either sense but provable by self-evident steps from a self-evident proposition. A priori in the narrow sense: self-evident; roughly, adequate is (a) 1 = 1, priori in understandingor a sufficientisan adequatea . my car ground for A (b) either 1 =sense: (a) based on red, (c) the strict 1 justification; belief based on such understanding constitutes understanding of a directly self-evident proposition, or theorem of sentential logic, is direct self-evidence.) (b) provable by (not knowledge. (This basic case indirectly simple) modus ponens steps too many, andbased on such an understanding via a self-evident entailment of the proposition in question byaself-evident PROPOSITIONS: proposition. A priori in the broad sense: not directly self-evident but either JUSTIFICATION: (a)indirectly self-evident, l.e., not self-evident but self-evidently entailed by a self-evidentin the strict sense A priori in the loose sense: not a priori proposition, or (b) based on an understanding of the proposition question Some Difficulties and Strengths of the Classicalin eitherVII but ultimately a priori, i.e., not-selt-evldsnt Viewin sense but provable by Distinctions III (Justification) Summarizing theself-evident stepsbe a priori or true). proposition. (the proposition itself need not from a self-evident KNOWLEDGE: JUSTIFICATION: BELIEF: ---- priori in the strict sense: (a) based (a) of adequate A priori in the strict sense: knowledge on an an a priori understanding is directly or indirectly self-evident, and proposition that of a directly self-evident proposition, or (b) indirectly based a such an is a priori justified in the strict sense. (b) constituted byon belief thatunderstanding via a self-evident entailment of the proposition in question byaself-evident proposition. A priori in the loose sense: knowledge (a) of a proposition that is not directly or indirectly self-evident but is provable by self-evidentthe loose sense: self-evident in the strict sense A priori in steps from some not a priori proposition, and (b) constitutedan understanding of the proposition in a proof. but based on by belief based on understanding such question (the proposition itself need not be a priori or true). A priori in the narrow sense: (a) held in an a priori way; roughly, priori an understanding (possibly an (a) adequate A(a) onin the strict 1 = 1, based inadequate priori Strict:basedbelief that sense: knowledgeon of an a understanding) of the proposition in question, indirectly self-evident, and is a priori proposition that is directly or understanding,or broad sense).and (b) of a1 or my car (b) belief that 1 = proposition that (in the narrow by a belief that is a priori justified in the strict sense. (b) constituted is red, based on AU of SEE (a) (b). KNOWLEDGE: Loose: based the broadunderstanding(a)priori proposition that A priori in on an sense: (a) held in an a(e.g.,way but A priori in the loose sense: knowledge of a (b) of an empirical proposition. insult/offended example would suit here) by is not directly or indirectly self-evident but is provable self-evident steps from some self-evident proposition, and (b) constituted by belief based on understanding such a proof. that is priori in the broad sense: not directly self-evidentarguably such th A neither a priori nor necessary but is but either (a)indirectly self-evident, there self-evident but In unjustifiably believe it. If l.e., not is indefeasible justification, this summarizing some apparently warranted conclusions regarding th Narrow: belief that nothing is a round square, self-evidently skepticism self-evidentseems plausible in plainly su in dealing with focus by a (as Chapter 10 will), of reason, we might entailedon how much proposition, or but the classic based (b) ultimately a priori, i.e., not-selt-evldsnt in either sense but Figure 4.2 Outline of on an understanding the a round/square. a four-dimensional conception of of priori that theisa not a characteristic mark of self-evident proposition. priori is coextensive with a either a priori includes the tion provable by self-evident steps fromthe necessary but or empirical Broad: the other hand,any tois no indefeasible when is necess (p) people tend proposition that is justification (some as If, subcategory: that there feel offended a priori a on they are butatnot every understanding of p is analytic. Apparent conversely, insulted. our a priori proposition solely open here), least One may believe simple self-evident tru A the strict sense: (a) based on on the uspriori in very secure justification an the basis of those truth basis of an understandingon adequate true thatunderstanding of a directly self-evident proposition, or (b) adequately gives not all propositions knowable of its both for believing concepts, despite ononbeing have adequatelyreason empirical. standing indirectlyare analytic: an basis of seen via a self-evident to think th them based its the understanding good understanding t such we we do believe them entailment everythingthem. of the analytic. The classical view seems correct in edge of a priori is proposition in question byaself-evident proposition. seems JUSTIFICATION: mistaken, however, in the idea that every necessary proposit priori, though probably not in the plausible ideaconclusions aregardin In summarizing some apparently warranted that every priori p A priori in tion is necessary. the loose sense: not a priori in the strict sense of reason,basedand Strengths of of the proposition in question we on focus on how Some Difficulties mightunderstandingthe much seems plausible in the c More but priori an coextensive IV Classical View VII knowledge positively, in addition to our the necessary that the aproposition Distinctions with having a prioribut includes is itself need not be a priori or true). Summarizing the (Knowledge) (the evident subcategory: on the basis of such knowledgeawe may is n priori know as a propositions, that any proposition that is truths that are at least ultimately a priori: not themselves self-evid conversely, but not every a priori proposition is analytic. App A priori in the strict sense: knowledge by an a priori self-evidently entailed by, or provable (a) ofself-evident steps from true that not all propositions knowable on the basis of adequ proposition that is directly or indirectly self-evident, and propositionconstituted by a belief that is beliefs, most inclearly certain logi (b) that is. Many of our a have seen the reason to standing them are analytic: we priori justified goodstrict sense. thi mathematical ones, are grounded in understanding in the indicated w everything a priori is analytic. The classical view seems corre KNOWLEDGE: the basis of understanding their content. Reason, then, as manif on priori in the loose sense: the idea that every necessary pro seems Amistaken, however, inknowledge (a) of a proposition that our capacity for understanding, is one ofbut is basic sources of belief, j is not directly or indirectly self-evident the provable by priori, though probably not ain the that the other that every a pr plausible idea three sources w tion, andself-evident stepsand, some self-evident proposition, and knowledge; from in way tion is(b) constituted by belief based on understanding such a proof.only in th necessary. explored do not, it enables us to know truths that hold not of ourMore positively, in addition to ourwhatever. a priori knowle experience but in any circumstances having evident priori in the narrow sense: basis of an a priori way; roughly, may propositions, on the such knowledge we A Strict: (a) knowledge that 1 (a) held(or an indirect = 1 a inpriori: not themselves self truths that on anat least ultimately are understanding (possibly inadequate understanding) SE: "1 based proposition in question, and (b)an a this belief Notes = 1 or my car is red"), whereproposition that is a priori of the of self-evidently justifiedby, theprovable by self-evident steps is (b) a(in the narrow or broad sense). strict sense. priori entailed in or Adequacy of understanding of a proposition cannot merely partial certain BELIEF: proposition that is. Many of our beliefs,bemost clearlyunderstan it is more knowledge grounded in understanding in the it, as w Loose: (a)than simply getting thesay, a theorem of expressingindica of, general sense of a sentence mathematical ones, are can analyze the grammar is provable the sentence, indicate something of sentential logic thatof sense: (a)theirinin (few, Reason,what it means priori in the broad an a priori on theA basis perhaps translate it intoheld content. way but then, Adeq examples, of an of understanding another language one knows well. as m and empirical proposition. simple)(b) steps from self-evident axioms, basic sources of bel where our capacity for understanding, is onesays but also being able ro apply implies not only seeing what the proposition of the (b)withhold its application understanding the proof. of cases. This this is based on tion, and knowledge; from) an appropriately wide range and, in a way that the other three sour treated in do not, it enables us to knowPhilosophical Perspeaiues (1999). some detail in my 'Self-Evidence; truths that hold not only explored PROPOSITIONS: ---- Some Difficulties and Strengths of the Classical View VIII The Power of Reason & Indefeasible Justification I Is reason powerful enough to be able to provide what even introspection seems (?) not to: so simple and There may be truths that arethey cannot be luminously self-evident that indefeasible justification (the "holy grail"!)? unjustifiably believed (when properly considered) skeptical arguments might be Plausiblepriori justification (even in the able to defeat a strict justification may Moreover, indefeasible for a posteriori claims. sometimes occur even sense) -- even for certain logical truths. Some Difficulties and Strengths of the Classical View VIII The Power of Reason & Indefeasible Justification II For instance, that (p) 1 = 1. see one could comprehendingly It's hard to and howunjustifiably believe p. consider p, yet Not all a priori justification is indefeasible. provides, when one adequately understands p. proposition that-"Branden Consider thethe kind of proposition thatexists". This may be I One might believe p (in part) for bad reasons, but that wouldn't undermine the justification reason But, surely, "Branden exists" doesn't express a necessary truth, much less an a priori truth! my justification is for believing that Whateverexists (what is it?), it doesn't seem Branden defeasible. But, it also doesn't seem a priori. (cannot help but) indefeasibly justifiably believe. Defeasibility & skepticism to be discussed later... ...
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This note was uploaded on 08/01/2008 for the course PHIL 122 taught by Professor Fitelson during the Spring '07 term at University of California, Berkeley.

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