In “Defeating the Dogma of Defeasibility” Ram Neta argues against all positions defeasible. Neta’s paper, which is found in Williamson on Knowledge[1], is a comprehensive argument against the alleged “defeasibility” of knowledge. Neta endorses an often neglected stance on knowledge: that knowledge is not capable of being defeated by future evidence. While I cannot cover Neta’s entire argument in a blog post I will get his position on the table, explain Williamson’s response to one aspect of Neta’s thesis, explain how Neta, willingly, embraces epistemological dogmatism, and then raise a problem with Neta’s account. According to Neta knowledge is indefeasible justified true belief (IJTB):
- S knows that p = S has a justified, true belief that p, and there is no true proposition e such that the conjunction of e and S’s actual evidence set E does not constitute a justification for S to believe that p (169).
Neta defends the IJTB account of knowledge by showing it can properly handle a battery of cases where non-knowledge gets counted as knowledge. I’ll leave those details to the reader and fast-forward to a part in Neta’s paper that Williamson takes issue with.
Are there counterexamples against IJTB? One counterexample is found in Williamson (2000: 219). This counterexample involves a person putting one black and one red ball into a bag (e), making 10K draws and getting a red ball every time (e’), resulting in rationally doubting whether a black ball was really put in the bag and not just a red ball made to look black by a trick of lighting. The initial knowledge is defeated by future evidence. Thus, knowledge seems defeasible.
But, not so fast says Neta. There are many ways the additional evidence (e’) can interact with the person’s beliefs: (i) the belief that p is true is lost, (ii) some of the initial evidence for p is lost, (iii) being able to reasonably form the belief that p on the basis of one’s evidence is lost. A person might lose knowledge that p in any of these ways. This is not a problem for IJTB because, “IJTB says nothing about what would happen to our epistemic subject if she were to gain an additional bit of evidence. It says that, if S knows that p, then, for any true proposition e’, the conjunction of our subject’s actual evidence set with e’ constitutes a justification for our subject to believe that p.” (171) For Neta, infallibility entails indefeasibility because, “Knowledge…is belief that is properly based on infallible evidence (indeed, on evidence that can be known—perhaps upon reflection alone—to be infallible)” (354). This means that a subject can know p only based on infallible evidence for p.
Williamson points out a fallacy in Neta’s argument for the idea that S knows that p only when it’s based on infallible evidence for p. It’s possible to deduce, according to Neta, from the assumption that S knows p on the basis of e that e is not misleading evidence for p. This makes a disjunction hold: either the subject can know the evidence is not misleading based on some further, independent, evidence e’ or e is infallible evidence for p. According to Neta the first disjunct leads to a regress because it’s possible to know that e & e’ are not misleading with regard to p, and this can be known based on further, independent, evidence e”, and so on. Williamson counters this assumption by saying it only shows that all cases of the first disjunct cannot be true, but it is possible that some cases are true. The result is that only some of the time the second disjunct is true, namely, in cases when the first disjunct is false. This does not show that the second disjunct is true all the time because, as Neta argues, the first disjunct is always false because it generates an infinite regress. According to Williamson the following is quite possible:
S knows that e is not misleading with respect to p on the basis of evidence e’ distinct from e; e is fallible evidence for p; S does not know that e & e’ is not misleading with respect to p on the basis of evidence e” distinct from e & e’; e & e’ is infallible evidence for p. (354).
So, it’s possible for e to be fallible evidence for p, yet for S to know p on the basis of e (i.e. when e is conjoined with e’). Williamson launches his second wave of attack against the assumption of entailment between infallibility and indefeasibility. If the evidence is infallible, then it’s the case that if S knows p on the basis of e, then p is true; possessing the evidence guarantees the truth of the belief. However, according to both Neta and Williamson’s views, the subject may not (and need not) be in a position to access or reason to the truth of the belief. So, even knowing that e is infallible evidence for p, it’s not clear that this entails indefeasible justification for p. Simply knowing that e is infallible does not entail that, “the conjunction of e with anything should constitute a justification for S to believe p” (355). It seems Williamson missed Neta’s disclaimer about justification, as Neta confides:
[T]here may be examples in which S is justified in believing that p on the basis of evidence that can be expanded into something that is not a justification for S to believe that p—justification itself may be defeasible. But knowledge is not defeasible, according to the IJTB theory (180).
Neta leaves justification as an outstanding, perhaps defeasible, position to develop. Williamson’s comments do bring out a worry with Neta’s account. Neta is committed to epistemic dogmatism. In fact, he embraces dogmatism. As long as an agent maintains her current evidence for her knowledge that p, future evidence will never justify disbelief in p. Being dogmatic about belief that p is OK because there is no epistemic cost, reasons Neta. Holding p as a settled belief and continuing to believe p in the face of new evidence, as long as one does not lose one’s current evidence, allows one to rationally continue knowing that p. What does it mean to lose evidence? If a true proposition in one’s evidence set becomes false it falls out of the evidence set. Beliefs once true can become false in light of new evidence (i.e. true evidence may falsify other true evidence once added to the evidence set). This means one must account for future evidence because it can cause one to lose one’s current evidence for the belief, and may, as a result, justify disbelief in p. Unless Neta embraces a view that factivity is absolute (i.e. once true, always true), it seems a cost of Neta’s view is that it sanctions a conflict: retaining evidence allows one to keep belief irrespective of future evidence, yet one can lose one’s evidence in the face of future evidence and so future evidence can significantly impact one’s current evidence. It seems: future evidence is no big deal with respect to one’s current evidence and yet a big deal with respect to one’s current evidence. Which is it?
[1] All page references and quotes are from Williamson on Knowledge.
There’s a new paper up on the papers page. It’s entitled Evidence, Reasons, and Epistemic Justification. Here’s the abstract:
- This paper puts forward a new account of epistemic justification. The Evidence and Reasons for Belief (ERB) thesis is offered as a response to deficiencies in a thesis endorsed by Stephen Kearns and Daniel Star (2008, 2009). In section 1, I substantiate the components of ERB in reference to the literature on the nature of propositions, facts, evidence, and normative reasons. Section 2 argues against the Kearns and Star thesis called Reasons as Evidence (RE). This is done by laying bare the logical structure of RE and showing that either of the conditionals in the biconditional endorsed by RE can be falsified using two cases inspired by Richard Foley (1991). In section 3, I argue for ERB in relation to ordinary linguistic intuitions and the ability of ERB to handle the two cases RE was unable to handle. Section 4 responds to a couple of objections to ERB, and section 5 summarizes and concludes the paper.
Update: The paper is now down for revision.
I’m not big on new year’s resolutions. I usually sit down and write out goals for the year, which I take to be more thought out and of greater likelihood of being accomplished than vague resolutions like, “I hope to exercise more this year.” One of my goals this year is to blog with greater frequency. Richard Chappell has a good post on the pros and cons of academic blogging. I agree with Richard that the pros of philosophy blogging outweigh the cons. So, these are some of the questions I aim to explore throughout the new year. These questions are related to the theory of epistemic justification and knowledge that I’m in the process of developing.
- Are facts truth makers or simply truth bearers?
- How does a propositional account of evidence accomodate non-inferential evidence?
- What is the relationship between epistemic and doxastic justification?
- What theory of the epistemic basing relation is most tenable (i.e., causal, counterfactual, doxastic, causal-doxastic)?
- How can the same epistemic reason be both normative and explanatory?
- How does my principle (evidence and reasons for belief–ERB) result in epistemic justification when all things are considered (e.g., all evidence and reasons are accounted for)?
- How is ERB a more defeasible principle of epistemic justification than its competitors?
- If evidence is a subset of the total facts about a case is one still rationally required to assess the total evidence in one’s evidence set when assessing the justification of a belief? If the total evidence principle is not rationally required, then what is the alternative principle that prevents irrational yet justified beliefs?
- What are my responses to the three arguments against foundationalism proposed by Howard-Snyder and Coffman (2006)?
- How is my version of foundationalism different from Alston’s two-tier model?
- How is my reasons and evidence-based theory of justification related to evidentialism of the Conee and Feldman type?
- How does my factive account of evidence defend itself against evidence is sometimes non-factive views?
- Does my account of justification lend itself to an account of knowledge? How does it handle the sort of counterexamples proposed by Neta in “Defeating the Dogma of Defeasibility” found in the book on Williamson’s theory of knowledge?
- How does my account of knowledge relate to or differ from the E = K thesis?
Here’s to the New Year!
As a quick update, I recently moved and I am getting settled. Lately I’ve been thinking about the nature of evidence. I plan to post on evidence and epistemology for a little while. I am now the editor of the evidence category at philpapers. My shift in focus to evidence has occurred as a result of reading Williamson, thinking that evidentialism is an interesting theory of knowledge that can be improved, and reading on evidence in the philosophy of science (probability) literature.
I close by drawing your attention to several recent discussions about evidence: here, here, here, and here.
This is the last in a series of posts on chapter 7 of The Philosophy of Philosophy. Section 7 touches on a subject I have spent some time researching and thinking about: reflective equilibrium (RE). Williamson uses a familiar line of reasoning to argue against RE. This reasoning goes as follows:
- Knowledge channel/methodology X (e.g. RE, judgment skepticism, epistemic conservatism) relies on psychological facts (beliefs).
- X assumes those beliefs are unproblematic.
- However, those beliefs are problematic (i.e. access to the beliefs is problematic, X cannot explain/defend the beliefs).
- So, X must be abandoned as a knowledge channel/methodology because X’s reliance on psychological facts is problematic.
In working through chapter 7 I have realized that Williamson keeps reapplying the reasoning above to different philosophical methodologies (1). However, there is something right about this reasoning. It is beneficial to the enterprise of philosophy to spotlight methodologies relying on unexamined assumptions. It is correct to label methodologies as problematic pending further defense of those assumptions. Williamson makes this point in connection with RE:
[O]ne has no basis for an epistemological assessment of the method of reflective equilibrium in philosophy without more information about the epistemological status of the “intuitions.” In particular, it matters what kind of evidence “intuitions” provide (2007: 244).
RE must defend the intuitions it relies on. The epistemic status of intuitions (as inputs in the RE process) must be elaborated. Based on his comments it seems Williamson is unaware that the literature on RE contains accounts addressing the epistemic status of considered moral judgments (i.e. RE’s version of intuitions). Some philosophers hold that intuitions constitute evidence like observations in science do. If this is the case, then ”observed facts are sometimes relevant evidence,” as Williamson objects, and this is no problem for RE. There are, however, problems with the analogy between intuitions and observation reports. I address these issues within the RE literature in the first half of my thesis. In the second half of my thesis I provide a positive account of the epistemic status of intuitions. It is my hope that this account can establish the evidential value of intuitions and directly address the concern Williamson raises. This makes it reasonable to rely on intuitions within RE methodology, as within RE are found the tools for explaining and defending the status of intuitions as evidence.
Notes
(1) I wonder if this way of thinking pervades the entire book. If so, what seems like a dynamic tome on philosophical methodology reduces to a one trick pony (i.e. externalism is true, or internalism is false).
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P.S. I will be on a brief hiatus from blogging. I am in the process of moving (fun, fun, fun). Also, I am trying to decide what kind of posting to do next. I will likely take a break from commenting on a chapter from a book and proceed on a topic-by-topic basis. Though, I must admit, I am tempted to tackle some of Moser’s Knowledge and Evidence. I am still kicking around that possibility.
I just posted a new paper in which I argue against the total evidence requirement on knowledge. The abstract reads as follows:
- A requirement on rational belief frequently invoked in epistemology and inductive logic is the total evidence requirement (TER). This requirement asks one to consult all evidence when making a determination about what one believes or the degree of confirmation to assign to a hypothesis. Despite the wide-spread use of the requirement there are many problems with it. After explaining the requirement in section 1 of this paper I motivate the requirement in section 2. In section 3, I highlight problems with successive interpretations of the requirement. This applies pressure to abandon TER or revise it. In section 4, I create the proportional evidence requirement (PER). This requirement revises the notion of what constitutes relevant evidence by making the notion proportional to the weight of evidence for a given hypothesis. After formulating two key principles behind PER I realize that one of the principles may not be an improvement over the commitments of TER. So, I revise one of the principles in PER to avoid such problems and create a requirement on evidence that is truly an upgrade over TER. I conclude this paper in section 5 by summarizing and indicating directions for future research.
Update: The paper is now down for revision.
In this post I will claim that Williamson’s analysis of epistemic conservatism is based on a mistake. Williamson’s mistake in chapter 7, section 6 of Philosophy of Philosophy (POP) involves including the belief that p among one’s reasons for believing that p. To flesh this out I first need to put a few things in place. Consider the principle of epistemic conservatism as formulated by Kevin McCain (2008: 189):
(PEC): If S believes that p and p is not incoherent, then S is justified in retaining the belief that p and S remains justified in believing that p so long as p is not defeated for S.
PEC captures the notion that one has a defeasible right to one’s beliefs. One loses one’s right to one’s beliefs given two conditions of defeat:
(DC1): If S has better reasons for believing that ∼p than S’s reasons for believing that p, then S is no longer justified in believing that p.
(DC2): If S has reasons for believing that ∼p which are as good as S’s reasons for believing that p and the belief that ∼p coheres equally as well or better than the belief that p does with S’s other beliefs, then S is no longer justified in believing that p.
Given PEC, the justification for believing p is analogous to the justification that S’s lacking a defeater provides. Lacking a defeater provides some justification, but it does not count as part of S’s reasons for believing. As McCain mentions, “S’s justification for believing that p is bolstered by her believing that p, but her belief that p does not count among her reasons for believing that p” (2008: 187). In short, belief that p cannot be used as a reason for believing that p. In a situation where S has another belief (or inclination to believe) that is inconsistent with p, S cannot use her believing that p as a reason to continue believing p. DC1 indicates that reasons for believing that ~p can act as defeaters and eliminate S’s justification for believing that p. DC2 indicates that if reasons for believing that ~p rival reasons for believing that p, and the belief that ~p coheres better with S’s other beliefs, then S has lost her justification for believing that p.
Williamson mentions that if intuitions are beliefs then they fall under epistemic conservatism. Do inclinations to believe also give one a defeasible right to one’s beliefs? What does epistemic conservatism council one to do when one has an inclination to believe something that is inconsistent with a belief one is currently committed to? Williamson uses a Gettier scenario to show that one cannot use an inclination to believe to arrive at a new belief. One can be inclined to believe something without believing it, and inclinations can conflict. When an inclination to believe something conflicts with a currently held belief, then, given epistemic conservatism, the currently held belief can be retained. Williamson (2007) arrives at this conclusion by claiming:
If I currently believe p, I am currently committed to the belief that any inclination to believe something inconsistent with p is an inclination to believe something false. I am not committed to the beliefs I am merely inclined to have in the way I am committed to my current beliefs (p. 243).
Given the PEC/DC1/DC2 package, an inclination to believe something inconsistent with a currently held belief (p), namely ~p, can serve as a reason to believe that ~p. That one believes that p cannot be used as a positive reason for retaining the belief that p in the face of reasons against that belief. Conservatism does not commit one to dogmatism. Simply because p is a belief (or because it is believed), and the reason to believe that ~p is arrived at via an inclination to believe, does not warrant retaining the belief that p. The inclination counts as a reason to favor ~p, so it is a potential defeater that must be overcome by reasons in favor of retaining p. Williamson does not offer any. What Williamson argues is that because an inclination is not fully believed it is not enough to overcome a belief that is actually believed or firmly believed. Williamson uses that fact that p is believed as a reason to retain p, which is a violation of PEC.
By contrast, what Williamson needs to argue is that an inclination to believe that ~p is not a reason that trumps the reasons in favor of believing that p. However, as the case is currently constructed, Williamson is not able to do this. In the Gettier case Williamson describes the reason Justin has for believing that knowledge is equal to justified true belief is that “Justin has been brought up to believe” that JTB theory is true. Is familial inculcation a reason for believing p that trumps the intuition that when presented with a Gettier case Justin judges that the Gettier subject has a JTB without knowledge? If anything, familial inculcation is often cited as a source of bias, blind belief and wishful thinking in the face of contrary evidence. This suggests that the inclination to believe that ~p, which is formed when presented with the Gettier case, is stronger than the reasons Williamson presents for favoring the belief that p. Thus, the intuition can serve as a defeater in this case, and epistemic conservatism councils Justin to abandon his inculcated belief and move to the new belief that the subject in the Gettier case has a JTB without knowledge or that JTB theory is false.
Big in the news right now is Ardi — the oldest known hominid skeleton (see the news here). This finding is thought to cast new light on early ancestors to humans and the upright origins of humankind. Without getting into a discussion on evolution I would like to use Ardi as a case study in scientific syntax. My wife is a chemist. She has often said that reporting research involves a great deal of massaging the syntax. How things are worded is important in reporting scientific findings. If things are not worded correctly findings can be overstated or understated. For example, if evidence e shows hypothesis h is probable one would not want to say that the evidence is conclusive in support of the hypothesis (unless the probability surpasses some threshold of conclusivness pre-established or generally understood by that scientific community). Scientific syntax needs to be properly hedged — words need to be properly chosen and arranged — to communicate semantics that are true to the findings. Syntax can even, dare I say, be used to get the findings to say things the evidence does not support.
Below are some quotes from the scientific findings as reported by the scientists in the magazine Science (2 October 2009 Vol. 326). I will place quotation marks around syntax of interest and briefly comment on the quote.
Despite its small cranial capacity, there is “tantalizing evidence” for advanced cranial based flexion in Ar. ramidus. (68e6)
It is interesting that an emotive word like “tantalizing” was used. Here is another quote that utilized a similar emotive word (“anxiously”).
More fossils “will” further advance our understanding of the CLCA, and we “anxiously await” their discovery. (74e7)
The emotive word choice makes the authors seem like they are excited about receiving more fossils, which “will” advance their understanding. There is a presumption in favor of evidence fitting theory and that what is found “will” bolster understanding. A critic might wonder whether there is some “making evidence fit theory” going on.
Now I will highlight the use of hedging in reporting scientific findings.
One of the instructive aspects of adaptive suites is the demonstration of what “must almost always” be a complex network of character interactions, even in reptiles and amphibians. “More often than not“, such interconnectivity is “likely to far exceed” relatively simplistic arguments such as somatic budgeting. (74e7)
What does “must almost always” mean? Is this like Brian Fantana in the movie Anchorman remarking about the effectiveness of Sex Panther cologne: “60% of the time, it works every time”? Also, what does “more often than not” interconnectivity is “likely to far exceed” mean? Does this mean greater than 50% of the time interconnectivity is “probably” going to outperform somatic budgeting. It is difficult to see what this hedging amounts to. Other classic hedging syntax includes: the records “suggest” X, it is now “equally clear” that Y, our comparative analyses of P “suggests” that this “probably” reflects Z. It is hard to track double-qualifications of likelihood and once identified it makes me wonder how much of the syntax is smoke-and-mirror methodology (i.e., purposely not showing one’s full cards). Another possibility is the double-hedging indicates lack of certainty on behalf of the scientists. This is more often than not probably what is going on (lol). Interpreting these findings over a period of years will determine what the findings really mean. It is ultimately the consensus of the scientific community that will settle the meaning of the evidence for various hypotheses about evolution.
Another thing that is clear from looking at the syntax of the Ardi findings is that a great deal of inferences occur in unearthing the fossils, putting together the skeleton, revising the skeleton until the scientists are happy with the reconstruction, building digital reconstructions of the entire skull, pelvis, and limbs to fill in the gaps and generate a fleshed-out virtual model and then from this virtual model drawing inferences about what hypotheses the evidence supports. For example:
The “digitally reconstructed” [Ardi] skull further allows “a variety of inferences” about African ape and hominid evolution. Cranial capacity…was “probably slightly smaller” than….The [Ardi] skull lacked the masticatory specializations of later Australopithecus, consistent with the dental evidence for an omnivore/frugivore niche lacking emphasis on hard and/or abrasive diets. Finally, comparisons of [Ardi] and extant African apes “suggest” that each is unique in aspects of its cranial anatomy. (68e6)
It would be interesting to calculate the probability of the inferences reported in the research. From the evidence the scientists infer that certain conclusions are correct or that certain hypotheses are confirmed. Many of the inferences are based on digital reconstructions. How accurate are the digital models? How likely are the models to reflect the actual creature? Is Ardi representative of that genus of animals? The sample size is so small that it makes me wonder if it is possible to infer from Ardi a conclusion about skull size in relation to Lucy (Australopithecus), especially because the sample size is so small in both cases. In my estimation the probability of these inferences from the evidence is mitigated by so many factors that the probability must be “reported” as small if the findings are to match the probability of the hypotheses conditional on the evidence. However, maybe I’m just playing with the syntax.
In this post, I will primarily summarize the rest of section 5. I will discuss intuition in detail in connection with section 6, but Williamson does raise some worries about intuition in section 5. Again, Williamson wields the evidence neutrality (EN) thesis. This time he uses EN to claim that it cannot be satisfied in relation to the evidential force of intuitions. A theory of intuitions needs to be able to distinguish weak from strong intuitions. This is because a theory of evidence will need to make choices between conflicting intuitions according to their evidential strength. However, according to Williamson, philosophers will tend to overestimate the strength of intuitions they have a vested interest in seeing succeed (i.e., intuitions that support their favored theory of knowledge, evidence or intuitions). Such theory-driven wishful thinking will result in a lack of “uncontentious decidability” as inquirers disagree whether someone (or, they themselves) have an intuition with a certain strength. A distinction was raised by Derek Ball here between the phenomenological and evidential force of intuitions. He argued it is not always clear which interpretation is at stake. Williamson is overtly talking about the evidential force of intuitions, but when talking about aspects of human psychology and vested interests his discussion could be interpreted in terms of the phenomenological force of intuitions. This is because human psychology is to blame for over or underestimating the strength of intuitions. There will be gradations in felt subjective certainty accompanying various intuitions according to whether the intuitions align with one’s professional and psychological interests. Even trying to compensate for bias will be difficult because one can see bias in another person easier than one can see bias in one’s own self. The phenomenological force of intuitions as experienced in consciousness is not a guide to resolving biases. Such factors make it difficult to reach an uncontentious view of the objective facts about intuitions (i.e., their strength in relation to a hypothesis). In fact, Williamson’s point seems stronger when the phenomenological reading instead of the evidential reading is considered. This aligns Williamson’s comments with Jonathan Weinberg’s comments in his paper on the hopelessness of intuitions (i.e., nothing within the intuition signal, or human psychology, is able to adequately recognize and correct cases of intuitions-gone-astray).
In the last half of section 5 Williamson goes into a discussion on the dialectical standard of evidence. Again, Williamson is trying to address the judgment skeptic. This view of evidence avoids the trap of resorting to psychological facts to try and resolve disputes about the evidence. In a dialectical context evidence is that which is uncontroversial in that debate or context. Evidence does not have to be foundational or uncontroversial across all contexts. Instead, it only needs to be uncontroversial in that context; if inquirers can agree over what counts as evidence, then what they agree on counts as evidence in that context. Williamson finds this view of evidence wanting because it results in conceding too much to the skeptic. Accepting as evidence only propositions that are true if one is a BIV, in order to have meaningful debate with the skeptic, does not have to lead one to a wholesale acceptance of skepticism about the external world. However, according to Williamson, giving the skeptic his or her premises forces one into a conclusion that one does not endorse. If one does not play the skeptic’s game, then the dialectical standard of evidence ends up being irrelevant. Another possibility is to switch to a non-dialectical standard. Given this standard the fact challenged by the skeptic is not disqualified as evidence. For example, one might take the fact that a Gettier subject lacks knowledge or the fact that there are mountains in Switzerland as evidence even though these facts are contentious to the skeptic. To ignore these facts is to violate the Carnapian total evidence requirement. Williamson wonders if such a move is a legitimate response to judgment skepticism?
Williamson’s conclusion is that we need to widen our evidential base. Even if intuitions were the most reliable forms of evidence it does not follow that we should restrict our evidence to just intuitions. Facts that the judgment skeptic hold as highly probable (in contrast to contentious facts about the existence of mountains) are not to be the only facts considered. We do not need to play the skeptic’s game just because she holds that only facts that are certain (because they align with the micro-physical structure of the universe) can be admitted as evidence. According to Williamson there is nothing wrong with continuing to claim knowledge of truths in contention. The “dialectic” is not the measure of all things. As Williamson says:
No methodology is proof against misapplication by those with sufficiently poor judgment.
It is not the job of good methodology to silence all people who propose, for instance, astrological predictions as truths. Instead, good methodology must separate good from bad intellectual practices. I imagine Williamson thinks he is doing this by contributing to the literature on philosophical methodology, by uncovering things like the consequence fallacy and other ways methodology goes astray. This is a useful endeavor, but because of Williamson’s clear bias for knowledge-first epistemology, epistemic externalism and a whole host of other theoretical commitments in analyticity, assertion, and so on Williamson’s work could be accused of the very thing he is arguing against, namely, proposing an account of methodology to philosophy in general (even giving the book the sweeping title The Philosophy of Philosophy) in a way that is highly uncontentiously decidable and violates the total evidence requirement by primarily using evidence from Gettier cases and revisionary metaphysics. As I have studied chapter 7 in POP I have kept coming back to inconsistencies between the content Williamson is arguing for and the methodology he is using in arguing for it. I’d be curious to know if anyone else has noticed the same inconsistencies.
Because there are many ideas of interest in section 5 of chapter 7 in The Philosophy of Philosophy (POP) I have decided to split this section among a couple of posts. In this first post I consider the following argument (p. 235) on how traditional skepticism narrows the base of evidence:
- Evidence is true (assumption).
- The proposition that I have hands (p) is not evidence in a skeptical scenario because it is false (given 1).
- According to the skeptic it is contentious that I am not in the skeptical scenario (assumption).
- So, it is contentious that p is evidence (2,3).
- Therefore, given the Evidence Neutrality (EN) thesis, p is not evidence (EN,4).
- Only the proposition that it appears to me that I have hands (p*) is evidence (assumption).
- Since both the common sense scenario and the skeptical scenario are consistent with all my evidence I cannot regard the former scenario as more probable than the latter (skeptical conclusion).
The moral of the story for Williamson is that the traditional skeptic can use EN, which is defined and explored in this post, to make it the case that the skeptical scenario cannot be ruled out; thus, it is not the case that I know I have hands or that the external world exists. One problem I have with Williamson’s formulation of the argument is the transition from p to p*. In 2, the proposition p is false because in the skeptical scenario it falsely appears to me that I have hands. My experience of hands is just an induced delusion at the hands of a mad scientist or an architect of The Matrix. In 6, the proposition p* is true. How can p be false because it falsely appears to me that I have hands and p* be true because it appears to me that I have hands? Is not falsely appearing the same as apperances being false? Even though in the skeptical scenario it is true to me that it appears that I have hands I cannot use that psychological fact to satisfy EN because it is contentious that p* is true because it falsely appears to me that I have hands. In the skeptical scenario p* is false as well as p.
Another feature of the argument I find puzzling is the jump from 5 to 6. Even if p is not evidence it is not clear that the only option for finding a proposition that can count as evidence is to resort to psychological claims. Even if, as I explained above, the shift from p to p* fails because p* is also false it is not clear that the only option for looking for true propositions is by turning inward. In a scenario like The Matrix there are glitches in the system that clue people, like Neo, into the fact that reality is not what it seems. A skeptic who uses a Matrix-type scenario can search for evidence in propositions about glitches in the fabric of space-time or computer-coded reality. In The Animatrix these things include:
a section of the house where it’s raining, cans that float in mid-air, doors that go nowhere, and best of all the characters get to slow down time and do leaps and twirls reminiscent of someone who’s jacked into the Matrix knowing how to bend its rules. http://www.thematrix101.com/animatrix/beyond.php
Williamson could make 6 a disjunction: the skeptic must use either a true proposition that exposes the falsehood of appearances or a proposition about appearances. Because propositions about appearances are not true (and only truths count as evidence) this forces the skeptic to use, for example, a proposition that cans float in mid-air (p**) as evidence that the skeptical scenario cannot be ruled out. This makes it the case that no matter which way the skeptic turns she cannot get her conclusion that the common sense scenario and the skeptical scenario are equally probable conditional on one’s evidence. This blocks the use of EN to generate traditional skepticism, which is not a bad thing because it is not clear that traditional skeptics endorse anything like “uncontentious decidability” among a community of inquirers. The traditional skeptic cannot and need not psychologize evidence.
