An inconsistency in the (supposed) prohibitions of philosophy Author: Terence Rajivan Edward, University of Manchester. Abstract. In different papers, David Liggins and Chris Daly tell philosophers what they should not do. There is no sign of them withdrawing any of these prohibitions, but I show that they fail to be consistent when asserting them. The inconsistency concerns when a philosopher should defer to the empirical findings of science. Someone who is beginning philosophy will hopefully think that there are some things that they should not do. They may turn to philosophers for guidance on exactly what they should not do. In different papers, the editors of the prestigious journal Analysis, David Liggins and Chris Daly, try to state some of these "prohibitions." 1 But I do not think that they are consistent when asserting these prohibitions. My aim below is to reveal an inconsistency in their work. One of their papers argues that philosophers should not defer to empirical research in the sciences (2011: 322). "Empirical research" here means research that involves observations using one or more of the senses, while to defer is to treat something as a higher authority. A philosopher defers to empirical scientific research if he or she: comes to a conclusion; discovers that this conclusion is incompatible with some empirical research in the sciences; and then says, "Given this empirical research, there must be a mistake within my argument." There may indeed be a mistake, but Liggins and Daly argue that incompatibility with scientific empirical 1 As I understand them, Liggins and Daly try to specify things a person should not do if they aim to achieve knowledge through philosophy. For convenience of expression, I have called these should-not claims "prohibitions." This may be a departure from the ordinary use of the word. 2 research does not in itself establish that there is a mistake. Even if the empirical research is completely accepted by a scientific community, they think that it is not necessarily true that the philosophical argument is mistaken (2013: 608). What else should philosophers not do? Another paper by Liggins and Daly argues that philosophers should not oppose all error theories (2010: 211). Error theories are theories which say that propositions of a certain type are false. For example, an error theory about value judgments says that all value judgments are false. (It is false that killing is bad, it is false that killing is sometimes bad, it is false that university education is a good thing, and so on. Here we do not need to inquire into exactly when a judgment is a value judgment.) Let us examine the justification for this second prohibition, the prohibition against opposing all error theories. Liggins and Daly write: Philosophers need to take care that their chosen objection to a given error theory does not prove too much by yielding a more general objection that applies to any error theory. This is because error theories about certain discourses are compelling: we should be error theorists about, for example, astrology, palmistry and numerology. (2010: 211) Liggins and Daly go on to criticize certain philosophers for doing what they must not do: for objecting to all error theories and thereby not supporting error theories about astrology, palmistry and numerology. But this kind of attack contradicts their demand that philosophers not defer to empirical research in the sciences, because it is empirical scientific findings which lead to these error theories. Let us look at the details of their attack to flesh out this point. I shall focus on how they criticize Hilary Putnam. Putnam argues against an error theory about value 3 judgments (1983: 177). But, according to Liggins and Daly, Putnam's argument entails a rejection of all error theories. Here is what they say about Putnam's argument: We do not pretend to understand fully all of Putnam's above remarks. But we understand this much: there is nothing specifically about values in the lessons that Putnam draws... Putnam's argument thereby proves too much. (2010: 211-212) Liggins and Daly do not claim to fully understand Putnam's argument. But they understand that the argument also works against attributions of error to astrology, palmistry and numerology. This is enough for them to know that Putnam's argument is a bad one, or so they believe. Liggins and Daly's response to Putnam can be reconstructed as two premises and a conclusion from these premises: (1) Any philosophical argument that is incompatible with error theories about astrology, palmistry and numerology is a bad argument, because empirical scientific findings reveal these things to be false. (2) When opposing an error theory about value judgments, Hilary Putnam makes a philosophical argument that is incompatible with error theories about astrology, palmistry and numerology. Therefore: (3) When opposing an error theory about value judgments, Hilary Putnam makes a bad argument. Note that Liggins and Daly do not fully state premise (1) in their writings. They state that it is uncontroversial that astrology, palmistry and numerology consist of false 4 claims, but they do not state why. This is an invitation to readers to suppose that, for Liggins and Daly, it is empirical scientific findings which reveal this. 2 Their (1) to (3) response is precisely the kind of deferring to empirical scientific research which Liggins and Daly elsewhere say they are against. They understand enough of Putnam's argument to realize that it is inconsistent with error theories about astrology, palmistry and numerology. They think that empirical research from science justifies these error theories, and so they dismiss Putnam's argument as a bad argument. Contrary to their own recommendations (2011: 322), they do not look at the details of Putnam's argument, to see whether it provides a stronger justification for rejecting these error theories. They are prepared to respond in the same way to any other philosopher who produces an argument that is inconsistent with error theories about astrology, palmistry and numerology: to dismiss it as a bad argument, without looking at other aspects of the argument. I shall conclude by spelling out the inconsistency as clearly as I can. In one paper, Liggins and Daly tell philosophers not to defer to empirical research from the sciences – the fact that a piece of philosophy is inconsistent with such research should not lead a philosopher to think, "There must be something wrong with this piece of philosophy." Liggins and Daly criticize various philosophers for thinking in this way (2010: 330-334; 2013: 608). But in another paper, they themselves demand that philosophers defer to some empirical research from the sciences, research which apparently reveals astrology, palmistry and numerology to be false. 2 It may be that, in another culture, readers would fill in the justification differently, e.g. we should be error theorists about astrology, palmistry and numerology because a sacred text instructs us to. But in the culture which Liggins and Daly are operating within, readers are going to fill in an empirical scientific justification. If Liggins and Daly were against this, they would have said so. 5 References Daly, C. and Liggins, D. 2010. In defence of error theory. Philosophical Studies 149: 209-230. Daly, C. and Liggins, D. 2011. Deferentialism. Philosophical Studies 156: 321-337. Daly, C. and Liggins, D. 2013. Animalism and deferentialism. Dialectica 67: 605609. Putnam, H. 1983. 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