Let me summarize what I argued in Chapters 3, 4 and 5 (the present chapter). In Chapter 3, I argued that attempts to show that intuitions do not play a role as evidence in philosophy fail. In Chapter 4, I argued that using the fact that we have an intuition as evidence from a thought experiment is a common practice. To show that we do so for methodological reasons, I argued in this chapter that there is a methodological constraint on evidence in philosophy. I first showed that there are methodological constraints in the sciences (sections 5.2 and 5.3). Given that academic philosophy is similar to the sciences in relevant aspects, there are likely to be methodological constraints on our evidence in philosophy as well. I considered several possible methodological norms and then suggested that a norm according to which we ought to use evidence that is relatively easy to access can explain why we appeal to the fact that we have an intuition as evidence from thought experiments even if we endorse the Inclusive View
(sections 5.4 and 5.5).
I mentioned in Chapter 3 that Williamson [140] thinks appealing to psy- chological facts opens a gap which is not easy to close and causes scepticism.25
I will now show how what I have argued in chapter 4 and in this chapter addresses this problem.
As a first reply to the worry of scepticism caused by the appeal to facts about our psychology, note thatprima facie, there is nothing special about the gap between these facts and facts about the world: we often appeal to the fact that some theory is simple as evidence for its truth, we often use semantic facts as evidence for metaphysical facts, and we use syntactic facts as evidence for semantic facts. These strategies all open a gap which has to be closed and, according to many philosophers, can in fact be closed.
Here are some examples in more detail. Most scientists as well as philoso- phers think that, other things being equal, the fact that a theory T is simpler
than an alternative theory T* is a reason to choose T over T*.26 According to
Elliott Sober, philosophers take the simplicity of a theory to be evidence for it’s truth:
Scientists sometimes choose between rival hypotheses on the ba- sis of their simplicity. Non-scientists do the same thing; this is no surprise, given that the methods used in science often reflect pat- terns of reasoning that are at work in everyday life. When people choose the simpler of two theories, this ‘choosing’ can mean different things. The simpler theory may be chosen because it is aesthetically more pleasing, because it is easier to understand or remember, or because it is easier to test. However, when philosophers talk about the ‘problem of simplicity’, they are usually thinking about another sort of choosing. The idea is that choosing the simpler theory means regarding it as more plausible than its more complex rival. [109, p. 13]
To take a second example, one of Williamson’s [140] concerns is to make clear that the (main) subject matter of philosophy is neither language nor concepts. Philosophy is as much about the world as any other science. Never- theless, Williamson thinks that it is sometimes useful to study the meaning of our words and the semantic structure of our sentences when we are interested in metaphysical facts. Since in philosophy, we have to reason ‘in areas where it is very hard to distinguish valid from invalid reasoning’, we must pay atten- tion to the semantic form of the premises, conclusion and intermediate steps, which requires semantic beliefs and sometimes explicit testing of these beliefs. Because semantic theories ‘have the great methodological advantage of being comparatively easy to test in comparatively uncontentious ways’ and hence are easier to test than facts about the world, we sometimes have to engage in
26Simplicity can be understood in many ways. It may stand for the paucity of parameters,
for theoretical plausibility or elegance, communicability, metaphysical parsimony and many other things. See Baker [5], Zellner et al. [143].
semantic theorizing.27 The semantic facts can then be used as evidence for
metaphysical facts, according to Williamson.
The attempt to provide a semantic theory that coheres with a given metaphysical claim can therefore constitute a searching test of the latter claim, even though semantics and metaphysics have different objects. [140, p. 285]
As a third example, take facts about the structure of ordinary language on the one hand and semantic facts on the other hand. Philosophers sometimes take syntactic facts to be evidence for semantic facts, for instance in the de- bate about the nature of propositional attitudes. Throughout the history of philosophy, the available views were variations of relational views of proposi- tional attitudes. According to these views, propositional attitudes are relations between a subject and a propositional content (be it an abstract object as ac- cording to Frege and Russell or a psychological object in a Fodorian language of thought). The problem with relational views is that they do not meet all widely accepted adequacy conditions for propositional attitudes. Quine and others have come up with non-relational dispositional or functional accounts of propositional attitudes. These views, however, face the difficulty that they do not match the structure of ordinary language attitude attributions. Accord- ing to ordinary language, we can conclude from the fact that Jones believes that Bill will be late both that there is something that Jones believes and that there is someone who Jones believes will be late. Non-relational views cannot account for this fact, because they cannot account for the fact that we can quantify over the predicate’s that-clause and over the subject position of the embedded sentence.28 Robert Matthews summarizes the non-relational view and its main challenge as follows:
What looks to be a relational predicate, they argue, is in fact a monadic predicate in which the constituent terms are semantically
27Williamson [140, p. 284-285]. 28See Matthews [83, p. 1-2].
‘fused’, such that we can imagine these terms being linked by in- visible hyphens (e.g., believes-that-Bill-will-be-late) [. . . ] if we are going to be non-relationalists about the attitudes [. . . ] then we are going to have to find some way of abandoning the assumption shared by relationalists and non-relationalists alike, that the adicity of propositional attitudes must match the adicity of the predicates by which we standardly attribute them. [83, p. 1-2]
It seems to claim that we should not appeal to facts about our psycho- logical states because there is a gap between these facts and the content of our psychological states is not sufficient to make the case against this practice. There is a similar gap between facts about theoretical virtues, semantic facts, or syntactic facts on the one hand and facts about the subject matter we are actually interested in on the other hand. However, we often appeal to facts about theoretical virtues, or to semantic or syntactic facts as evidence.
Closing the gap between evidence that is easier and evidence that is harder to access might not be that hard. However, we should not expect one general strategy to do the work here, because the kinds of evidence that are easier to access as well as the kinds of subject matter our theories are about differ. It seems that each link needs to be defended or proved unreliable independently (they might run parallel of course).
Whether semantic facts mirror metaphysical facts and whether the struc- ture of language tells us something about its semantics are both ongoing sub- jects of discussion in philosophy. As an example of the second, I mentioned the debate about propositional attitudes. As to simplicity (both parsimony and elegance), philosophers have been giving both a priori and a posteriori argu- ments as to why, other things being equal, the simpler theory is more likely to be true.29 Amongst the a priori justifications there are theological (e.g.,
Smart [107]), and metaphysical (e.g., Lewis [73]) justifications and such that claim that there is intrinsic value in simplicity (e.g., Sober [109]). However,
philosophers have also given naturalistic justifications. The important point to note is that philosophers have been trying to close these gaps, which requires philosophical work.
Let us see how the gap between facts about our psychological states and the contents of these states could be closed. This case should be less controversial than any of the cases mentioned above. The reason is that if our intuitions (e.g., from thought experiments) are reliable, we are both reliable at getting the fact thatP right as well as at having an intuition thatP, because whenever we get a fact that P right (e.g., in the case of thought experiments) we get it right by having an intuition. In other words, whenever we know thatPin these cases, it is also true that we have an intuition thatP. Hence, any argument for why we are reliable in judging in a certain area or as part of a certain method is also good as an argument for why we can take the fact that we have an intuition as evidence. Whether we are reliable has to be shown separately for any area or method, it certainly does not generalize to intuitions in general, but I was concerned with intuitions in thought experiments only.
Jessica Brown [10] argues that we can close this gap within an externalist picture of epistemology, which I mentioned in Chapter 3. Brown refers to per- ceptual evidence and claims that we might be able to use the same strategies in the case of intuitions. Brown compares the gap we are concerned with with a gap between psychological evidence from perceptual experiences and facts about the world. Just as we can close the gap between perceptual experience and facts about the world, we can close the gap between facts about our in- tuitions and facts about the world by appeal to an externalist approach to justification and/or knowledge:
Suppose that whenever one has such an experience, one forms an appropriately related belief. For instance, that when one has an experience as of a large barking dog in front of one, one forms the belief that there is a large barking dog in front of one. On an ex- ternalist approach to justification, such as reliabilism, as long as
the appropriate external relations hold, the beliefs so formed are justified. One might hope to apply this solution to the gap prob- lem in the case of perception to the gap problem facing the psy- chological view of thought-experiment evidence. Suppose that, in fact, the method of forming beliefs about the nonpsychological sub- ject matter of philosophy on the basis of the relevant psychological propositions is reliable. Combining this supposition with a relia- bilist approach to justification has the result that beliefs formed in this manner are justified. [10, p. 513]
I argued in sections 5.4 and 5.5 that there is a methodological constraint on evidence in philosophy which explains why we appeal to the fact that we have an intuition as evidence from thought experiments even if we endorse what I called theInclusive View: the Accessibility Norm. Note that the Accessibility Norm could also explain why we often appeal to facts about theoretical virtues, to semantic or syntactic facts. It seems that it is easier to access facts about the simplicity of a theory than to access the truth of the theory. Similarly, it seems easier to access facts about semantics than metaphysical facts, and it seems easier to access facts about the structure of ordinary language than to access semantic facts. To retreat to pieces of our total evidence that are typically or in fact relatively easy to access is a common strategy in philosophy.
I presupposed that we do not have to endorse the sceptical consequences some experimental philosophers draw from their studies and that philosophers’ intuitions are more reliable than laypeople’s intuitions (see Introduction). If we appeal to the fact that we have an intuition, however, we have to argue from this psychological fact to a fact about the world. Since we appeal to the fact that we have an intuition for methodological reasons only, it follows that we have to close the gap for methodological reasons only. This, however, does not affect our knowledge, and hence does not constitute a sceptical threat.
While we know that a thought experiment undermines the target theory, we might not have succeeded in refuting the theory. I showed in Chapter 4 that
there are several ways to challenge an intuitive counterexample and to argue that a particular intuition does not lead us to the truth or is not inconsistent with the target theory. I think that for methodological reasons, we have to show that these strategies do not apply for any particular case we are concerned with. It might, therefore, be hard to show that a counterexample is not merely intuitive but instead undermines a certain theory. This does not seem to come as a surprise. The history of philosophy proves that it is very hard to refute a philosophical theory.
Reflective Equilibrium and
Counterexamples
Abstract
Reflective equilibrium has been considered a paradigm method involving intuitions. Some philosophers have recently claimed that it is trivial and can even accommodate the sort of scepticism about the reliability of intuitions advocated by experimental philosophers. In order to see whether it is as trivial as some philosophers think, I discuss whether reflective equilibrium is compatible with different views concerning our practice of appealing to intuitions as evidence from thought experiments. I first argue that reflective equilibrium is not compatible with scepticism about the reliability of intuitions. I then argue that reflective equilibrium is compatible with the view I have defended in Chapters 3 to 5, but that we have to make some more specific methodological claims to account for it.
6.1
Introduction
Reflective equilibrium has been considered a paradigm philosophical method involving intuitions. It has been extensively discussed in normative ethics and political philosophy. The key idea of reflective equilibrium as introduced by
John Rawls [99], [100] for moral and political philosophy is that we test our moral judgments (or intuitions) and moral principles against each other and revise and refine both when they are inconsistent.1 In the literature, ‘reflective
equilibrium’ ambiguously stands for the method of reflective equilibrium and for thestate in which all our beliefs are in equilibrium, i.e., in which we have reached coherence amongst our beliefs. I am concerned with the method of reflective equilibrium (MRE in what follows).
Without specifying what exactly they mean by it, philosophers in all areas of research frequently use the term ‘reflective equilibrium’ when they mention the methods and aims of their inquiry. It has been suggested that ‘reflective equilibrium’ is nothing more than a metaphor for the rational performance of philosophy: for taking into account all relevant information available and for working out the most plausible, coherent, and comprehensive theory of the sub- ject matter under investigation.2 Michael DePaul [25] and Peter Singer [104]
suggest that it could even be compatible with scepticism about the reliability of intuitions, i.e., with a view according to which we ought not take our intuitions into account at all.
I am interested in the question whether MRE is as trivial as some philoso- phers think or whether it gives us some helpful methodological advice. If it gives us methodological advice, having followed reflective equilibrium could provide us with some evidence as to the truth of the resultant theory which is relatively easy to access and hence is evidence we ought to appeal to in order to establish this theory (as argued in Chapter 5). Different views concerning the role of intuitions that have been defended in the recent debate on the method- ology of philosophy have not yet been reflected in the literature on MRE. The current chapter looks at MRE in particular in light of the distinction between the appeal to the content of an intuition and the appeal to the fact that we
1Even though the term ‘reflective equilibrium’ was introduced by Rawls, Nelson Good-
man was the first to discuss the method behind the name in ‘The New Riddle of Induction’ (originally 1953) in hisFact, Fiction, and Forecast [47]. Goodman defends reflective equi- librium as a method of justification in logic and inductive reasoning; see also Resnik [101].
have an intuition.
The chapter consists of two main parts. In the first part (sections 6.2 to 6.4), I present MRE as it has been discussed in moral philosophy (section 6.2) and apply it to epistemology, more precisely to Sophie, a fictional philosopher who thinks about the Gettier Cases as counterexamples to the theory of knowledge as justified true belief (the JTB theory of knowledge) (section 6.3). I then specify what philosophers mean when they say that MRE is trivial (section 6.4). In the second part (sections 6.5 and 6.6), I look at different views philosophers hold in the current debate concerning the role of intuitions in philosophy. I argue that the sceptical view according to which intuitions ought not play any role in philosophy is not compatible with MRE (section 6.5). I moreover argue that the view I defended in Chapters 3 to 5, according to which we ought to appeal to the fact that we have an intuition as initial evidence from thought experiments is compatible with MRE, but more specific methodological claims have to be made in order to distinguish it from other views and in order for MRE to serve as a methodological guide (section 6.6). I conclude that MRE is not as trivial as some philosophers think (section 6.7).