Putnam: Introduction part I

40 Replies to “Putnam: Introduction part I”

1. Chris,
   One kind of anti-realist argument wrt mathematics is based on worries about our epistemic access to causally isolated mathematical entities. Is there an analogous argument wrt ethics that has enjoyed an analogous amount of attention or popularity?
   Gil Harman once told me (among others) that his famous argument about moral observation from chapter 1 of The Nature of Morality was inspired by a conversation with Paul Benacerraf in which Paul remarked on the parallel between moral properties and mathematical entities with respect to epistemic access through causal interaction.
   In any case his argument does rely on the sort of worry that people have about abstract objects – if moral properties don’t do any causal work over and above the properties on which they supervene, and if they are not reduced to those properties, then they will not be necessary to explain anything, including moral judgements. (This is pretty rough as a summary of the chapter, but I think it suggests the parallel.)

2. Kris,
   I wondered about your question as well.
   There is certainly one kind of argument againt moral realism that is not present in arguments about the reality of mathematical objects. I have in mind Humean worries about morality and motivation. Moral judgments necessarily motivate (or so Hume says) but no belief that X is the case will neccesarily motivate. So moral judgments do not express beliefs, but serve some other purpose.
   Mackie goes even further (if I recall correctly) when he argues for an error theory for morality, but seems to allow mathematical facts to be in some sense real when he points to how the latter allow us to manipulate reality so well.
   So there does seem to be some kind of difference between the two cases.

3. About the first argument. I don’t much at all about the debates in philosophy of mathematics, but I can still vaguely see how the argument would go. So, you think that there are for instance different geometric systems with different axioms – Euclidean and a variety of Non-euclidean ones. Then you might say that it is pretty much pick-and-choose on the basis of your interests which one you choose to apply. And, different systems have been accepted in different inquiries – in agriculture, physics and so on – on the basis of their suitability. Then you might think that there is no further question about which of the systems is ‘true’ from the perspective of the universe, full stop, but rather geometric truth is only relative to a system within some interest based inquiry. That might be something along the lines Putnam would have in mind here.

4. Note that in the Harman piece Mark refers to, Harman claims that there is an important difference bewteen ethical claims and mathematical ones. Mathematical principles figure into the best explanations of observations of physical phenomena; ethical principles do not figure into the best explanation of any observations. So he says.

5. I wish Putnam had elaborated on this remark because, on its face, I don’t see the analogy between these two forms of anti-realism as being that tight. As Scott noted, the internalist/Humean argument seems not to apply to mathematics; I’m not sure what it would mean to say that mathematical judgments are intrinsically motivational. As for the other arguments, the premises typically appealed to in arguments for moral anti-realism don’t seem to hold true in the relam of mathematics: relativism or disagreement might (as Jussi pointed out) hold at the theoretical level, but isn’t the strong convergence in ordinary thinking about, say, arithmetic evidence *for* mathematical realism? Indeed, it seems to me that mathematical realists get a lot of traction from inferring the existence of mind-independent mathematical truthmakers from the apparent epistemological objectivity of mathematical judgments (exactly the opposite of the apparent subjectivity of moral judgments). Moral realists also get in trouble with supervenience, but I don’t think that mathematical realists propose that the mathematical supervenes on the physical; rather the mathematical is sui generis. That of course raises the question of causal access to these entities, which in fact has been the basis of mathematical non-realism (Benacerraf and Field, for instance).

6. “I’m not sure what it would mean to say that mathematical judgments are intrinsically motivational”
   Perhaps they can be motivational (though not in an internalist sense) in the same way that logical judgments are. Rules of inference in natural deduction, for instance, provide norms for reasoning: specifications of the sorts of inferences one is forbidden and permitted to draw. Similarly for mathematical inferences (which are largely logical) including rules governing mathematical induction and so on.
   I suppose you’d have to be an internalist about rationality to take them as internally motivating (I’m incidentally not sure why one would be an internalist about ethics and not an internalist about rationality). Still there is a parallel with ethics.

7. Mike,
   But doesn’t the internalist argument for moral irrealism rest on something stonger than what you’re describing: that the sincere acceptance of a moral judgment produces a disposition to act in accordance with it? I don’t see anything ‘motivational’ (if motivational means ‘productive of action’) about rules of inference licensing certain conclusions. The ‘product’ here isn’t a motive, is it? But I fear I’ve misunderstood your suggestion.

8. I think Mike is right — the analogy with internal motivation is not exact, but it’s important. You could not have a mathematical concept unless you were inclined to infer from propositions involving it certain other propositions. Some kind of conceptual role semantics seems almost forced on us, for the case of mathematical concepts. That doesn’t lead straight to antirealism, though, does it?
   Kris, I don’t suppose Putnam actually says what arguments he has in mind, does he?

9. Hi guys,
   Thanks everyone. This is very helpful. I’ll have another post up in a few days, on chapter one.
   Jamie, Putnam hasn’t yet identified the arguments he’s worried about it. But it’s strongly suggested by the introduction that the basic argument he wants to reject will go like this:
   (1) There are no mathematical or ethical objects (numbers, sets, ‘objective values’, etc.)
   (2) If (1), then mathematics and ethics are not ‘objective.’
   (3) So mathematics and ethics are not ‘objective.’
   I’m guessing that Putnam will reject (2). Presumably the anti-realist arguments he has in mind will spend most of the time defending (1) and will take (2) for granted.

10. The practical nature of morality, its connection with motivation, is a salient difference from mathematics. But exagerating its significance can obscure a deeper parallel. Morality and mathematics each involve a distinctive modality. Just as there is a moral ‘must’ there is a mathematical ‘must’. Just as you must keep your promises, two plus two must equal four. In each case the nature and source of this modality is obscure and this obscurity can give rise to a certain kind of puzzlement.
    Appreciating how certain questions about morality and mathematics are about modality reveals further parallels. Notice, for example, that there are constructivist explanations of mathematical and moral modality respectively.
    Putnamian doubts about explaining the ‘objectivity’ of morality and mathematics in terms of distinctive objects corresponding to these domains (a doubt that Field has independently developed with respect to mathematics) fit this general pattern as well.
    Another alleged difference between morality and mathematics is that there seems to be no analogy in mathematics to the argument from diversity. This is just an oversight. Examples are unobvious but are easy to find if you generalize the potential sources of diversity. Just as there is or could be a diversity of conflicting values, there are or could be a diversity of progressions and hence a diversity of conflicting identifications of numbers with progressions. In each case it is argued that it is arbitrary to suppose that one and not the other of the conflicitng alternatives is genuine. This in turn, given some plausible background assumptions, gives rise to a certain kind of puzzlement.

11. Mike C., you say,
    “But doesn’t the internalist argument for moral irrealism rest on something stronger than what you’re describing: that the sincere acceptance of a moral judgment produces a disposition to act in accordance with it?”
    But similarly for mathematics, Mike. Of course, there is a limit to the parallel here. But I think one might urge that a sincere acceptance of a basis step that 1 has property F and an inductive step that, for all n, if n has property F then n+1 has property F, would or should *dispose* you to accept that 2 has property F.
    The presumed parallel would have you believe that a (perhaps ideally) rational agent is motivated to accept that 2 has property F. So it *looks* like there is room to talk about motivation in mathematics case. But maybe I misunderstood you here.

12. Mike A.,
    The Humean moral anti-realist argument claims that the only relation that can explain the apparent motivational force of moral judgments is that desires cause the impetus to act on our moral judgments (and because desires aren’t truth-bearers, moral realism can’t be true, etc.) So I guess I hear you saying something like this: The Humean moral anti-realist takes as the relevant target of explanation how moral judgments result in dispositions to act. But you’re not claiming that mathematical judgments result in dispositions to act, but in dispositions to accept further judgments that can be inferred from existing mathematical judgments. So there’s where the parallel is not exact. But you also seem to think that the apparent ability of mathematical judgments to produce futher mathematical judgments somehow helps to answer the Humean moral anti-realist argument. But it’s not clear to me where the help comes from, since the Humean moral anti-realist need not deny that mental states have causal relations with other mental states; her position is specifically directed at the power of moral judgments to produce motivation to act (i.e., it’s not a general skepticism about the causal powers of cognitive mental states). (I’m not signing on the Humean, BTW, since it seems to me to presuppose the very psychology it’s supposed to defend, but that’s another topic.)

13. First things first, I guess. You say,
    “But you’re not claiming that mathematical judgments result in dispositions to act, but in dispositions to accept further judgments that can be inferred from existing mathematical judgments.”
    But accepting a further judgment, I say, is itself an action. You can accept or not. Compare: you can accept a bribe or not. Accepting a bribe is itself an immoral action on some moral views. So I’m claiming that mathematical judgments do result in a dispositions to act.

14. Mike,
    Our original concern was with the relevant parallel (or lack thereof) between the arguments for moral and mathematical anti-realism. And I agree that accepting a bribe is an act. My only point is that’s not what Humeans who argue for moral anti-realism on this basis mean when they assert, e.g., that moral judgments intrinsically motivate action. They clearly mean ‘act’ in the ‘move your visible body’ sense.

15. Here’s something that has started to puzzle me more and more. A lot of people, the comments in this thread included, take the Humean judgment-internalist arguments to be relevant for the realism/anti-realism debates. I wonder why – what is the connection? As far as I can see the internalism debate is about what kind of mental states our moral judgments are, a disagreement in moral psychology, and the realism debate is a metaphysical question about what kind of properties there are in the world. Now, I don’t see an easy argument from a premise of what our mental states are to a conclusion what there is in the world. But maybe I’m missing something.

16. ” that moral judgments intrinsically motivate action. They clearly mean ‘act’ in the ‘move your visible body’ sense”
    I wonder why that is the way to interpret Hume on this score? I can’t see any principled difference between overt and covert actions that would motivate the distinction for Hume. It seems like the moral judgment that accepting a bribe is wrong would not motivate my action of not accepting unless I desired to act morally. It seems just like any overt action.
    In the mathematics case, not accepting that 2 has F would violate principles of mathematical induction, but that would not motivate me to accept that 2 has F unless I desired to act rationally.

17. I don’t think Putnam has antirealist arguments based on internalist considerations in mind when he draws the parallel between metaethics and philosophy of mathematics. Putnam’s focus in “Ethics Without Ontology” is *much* broader. (I think it helps to remember this when reading his later books.) He aims to undermine all antirealist arguments that presuppose that the senses of words that populate realist/antirealist debates–such as ‘objecthood’, ‘exists’, ‘identity’, etc.–are exclusively fixed by the senses they have in their uses in the natural sciences. In this regard, I think his argument in “EWO” is very similar to his argument in “The Threefold Cord” against the intelligibility of debates about mind/body identity (or lack thereof).
    I have a very short review of Putnam’s “EWO” in this January’s issue of ‘Ethics’ that critiques Putnam’s use of this sort of argument in this context, but I don’t know how to link to it, since accessing it requires going through a proxy server. (If anyone else knows how to set up such a link, I would appreciate it. Am I allowed to just post the review here? I’m new to these things.)

18. Hi Kris. My apologies for getting to your post so late. After the section you quote (p. 1), Putnam goes on to say, “(Y)et philosophers who resist those [antirealist] arguments [in the philosophy of mathematics] often capitulate to them in [ethics].” Later, he says that “If there is a common element of my treatment of [philosophy of mathematics and ethics], it lies, I think in this: I see the attempt to provide an Ontological explanation of the objectivity of mathematics as, in effect, an attempt to provide reasons which are not part of mathematics for the truth of mathematical statements and the attempt to provide an Ontological explanation of the objectivity of ethics as a similar attempt to provide reasons which are not part of ethics for the truth of ethical statements; and I see both attempts as deeply misguided” (p. 3).
    I agree with some of the other commentators that what Putnam has in mind here is more general than, e.g., whether internalist-type anti-realist arguments in ethics are also used in mathematics. Consider the following (rough) General, Moral, and Mathematical Realist arguments from Ontology.
    General Form of Realist Arguments From Ontology
    1. Statements are objective and true only if they describe the world
    2. Statements describe the world only if there can be objects in the world that “correspond” to or “support” the statements, thereby “making” the statements objective and true
    3. Therefore, statements are objective and true only if there can be objects in the world that make them objective and true (1, 2)
    4. If there can be no natural objects in the world that make statements objective and true, then there have to be nonnatural objects in the world that make them objective and true (3, and assuming an exhaustive natural/nonnatural dichotemy)
    Moral Realist Arguments From Ontology
    5. Ethical statements are objective and (some are) true
    6. Therefore, there can be objects in the world, natural or nonnatural, that make ethical statements objective and true (3, 4, 5)
    Mathematical Realist Arguments from Ontology
    7. Mathematical statements are objective and (some are) true
    8. Therefore, there can be objects in the world, natural or nonnatural, that make mathematical statements objective and true (3, 4, 7)
    Putnam thinks that, traditionally, moral and mathematical anti-realists have wanted to reject 6 and 8. respectively. However, whereas moral anti-realists have also wanted to retain 1. and 2. and, therefore, have rejected 5., mathematical anti-realists have wanted to retain 7. and, therefore, have rejected 1. and 2. Therefore, the form of the anti-realist arguments are virtually identical (they each take the Realist Arguments, reject the conclusions, and so reject at least one of the premises), but their conclusions differ significantly.
    Putnam wants to say, I think, that while many anti-realists in ethics have “capitulated” to the anti-realist claim that ethical statements are neither objective nor true (because they have wanted to hold on to Ontological assumptions 1. and 2.), many of these same anti-realists, while doing philosophy of mathematics, have rejected Ontological assumptions 1. and 2. and have “resisted” giving up the conclusion that mathematical statements are neither objective nor true. He hopes that the “capitulators” in ethics can learn from the “resisters” in philosophy of mathematics by (i) holding onto the claim that ethical statements can be objective and true while (ii) rejecting the claim that ethical statements are objective and true only if there can be objects in the world that “make” them objective and true.
    At least that’s how I’m reading him.

19. I think Dan has the basic tenor of Putnam’s strategy spot on — that he wants to lend objectivity to moral judgments by way of some non-ontological account similar to what non-Platonic defenders of mathematical objectivity want to do.
    Jussi, I think you’re right about the motivational internalist point. But some internalists want to use their conclusion that moral judgments are non-cognitive states to refute realism, where realism is the claim that we can make true moral judgments: Since moral judgments are, according to the internalist, not truth-bearing at all, then there are no true moral judgments. That’s of course compatible with there being real moral properties. Does anyone defend metaphysical realism and non-cognitivism?
    Mike A.: Hume says that reason can produce no passions or volitions. For instance, “reason alone can never be a motive to any action of the will,” and that reason alone “can never oppose passion in the direction of the will” (Treatise 413) Furthermore, since in the arguments for this conclusion, reason is understood as the faculty for discerning relations of ideas or matters of fact, what Hume seems to be doing is understanding the impotence of reason (and by extension, any act of reason) as the inability to produce action in the ‘move the limbs’ sense (or the inability to produce whatever states serve as the causal antecedents of limb-moving). I.e., reason (cognitive mental states) can do exactly what you describe, generate further cognitive mental states. Your example would be one involving relations of ideas presumably. But they can’t generate action in the relevant sense.

20. Michael,
    probably not. There is a view for fame for someone. But, it doesn’t seem inconceivable to imagine that while a moral community once uses moral utterances to describe the existing moral properties and have corresponding, occasionally true, moral beliefs with robust truth-conditions, their practice deteriorates to expressing pro- and con-attitudes. In this case the linguistic meaning of the utterances migth retain their old truth-conditions and reference to moral properties while the use of these utterances would not be to express beliefs but desires. In this scenario internalism, non-cognitivism and realism would be true.

21. Hi Jussi. Thank you for all of your contributions to PEA Soup. I know that all of us here look forward to your helpful comments. You write, “[suppose] their practice deteriorates to expressing pro- and con-attitudes. In this case the linguistic meaning of the utterances migth retain their old truth-conditions and reference to moral properties.”
    If by ‘deteriorate’, you mean ‘completely deteriorate’, then I don’t see how the linguistic meaning of the utterances can retain their truth conditions and references to moral properties, in which case, I don’t see how such a view could be realist. If by ‘deteriorate’ you mean ‘somewhat deteriorate’, then such utterances (when used properly and literally) would continue to express beliefs (perhaps in addition to desires), in which case, the view would continue to be cognitivist.

22. Mike C., I said this,
    “In the mathematics case, not accepting that 2 has F would violate principles of mathematical induction, but that would not motivate me to accept that 2 has F unless I desired to act rationally.”
    Now I think you’re telling me there is no Humean problem with me (i) having no desire to act rationally and (ii) accepting that 2 is F on the basis of the mathematical induction.
    I can’t understand it. We agree (right?) that (1) accepting that 2 is F is something I do, it is an action (like accepting a bribe); it is not something that happens to me (like falling off a building), and (2) I need some motivation for performing the action of accepting that 2 is F. But (3) I’ve eliminated the only motive that seems relevant (i.e., a desire to act rationally).
    So is your view that Hume is arguing that I can perform (some) actions without any motive at all? Or do you want to say that accepting that 2 is F is not an action?

23. Here’s a thought about Jussi’s ‘deterioration’ scenario, and Dan’s reply; Jussi’s scenario is of course exactly what MacIntyre says has happened to Western moral philosophy since the Enlightenment, which makes it worth discussing I think. It’s implausible (isn’t it?) that there’s some sharp line at which an expression mutates from expressing beliefs to expressing desires. This is even less plausible if we think that the content of moral claims is somewhat ‘externalist’, i.e. fixed by moral theories which a speaker may only partially grasp. For if the ‘deterioration’ idea is right, then the public grasp of moral theory rots away slowly, it doesn’t die off all at once.
    Now, suppose this is true. It follows, I think, that the difference between realism and anti-realism about moral discourse ought to be a _vague_ one; and the difference between cognitivism and non-cognitivism in moral psychology ought to be vague as well. At present, however, these views are not framed in ways that would allow for vagueness: sentences have truth conditions or they don’t; they express beliefs or desires but not both.
    If any of this vagueness is even possible, then current theories are problematic, since they can’t capture the possible vagueness. What do people think about that idea? I’d like to know, since I’ve kicked around writing a paper on this topic.

24. Mike A.: I’m not defending anything at all here, apart from an understanding of Hume’s position and how it has been used in support of moral anti-realism. I understand why you want to call accepting a mathematical demonstration an “action”. My only points are (a) that Hume did not understand “action” in this way, and (b) those who (being influenced by Hume’s psychology) utilize motivational internalism to argue for moral anti-realism have more or less followed Hume’s understanding of the relationship between reason and action. I don’t think Hume’s understanding is that there are unmotivated actions, but that mathematical reasoning of the sort you identify does not result in “action” in Hume’s sense.
    Treatise II.iii.iii: “The understanding exerts itself after two different ways, as it judges from demonstration or probability; as it regards the abstract relations of your ideas, or those relations of objects, of which experience gives us the only information. I believe it scarce will be asserted, that the first species of reasoning alone is ever the cause of any action.”
    And later: “Abstract or demonstrative reasoning, therefore, never influences any of our action …”
    So Hume’s position is that accepting that 2 is F is not an “action” and hence needs no explanation for how it’s motivated. There is not, in his view, a mental state that mediates between your cognition that 2 is F and your accepting it. Or at least that’s the reading of Hume that seems best supported by the relevant texts.

25. Dan,
    thanks. You may be right. I just have the intuition that there are some predicates we can use to either express pro-attitudes or beliefs – say ‘cool’. Whichever one does probably depends on one’s communicative intentions, the context, and so on. And, if this is possible for an individual it could then also be for the group. But you might be rigth that the predicate might loose its former truth-conditions in the process.
    Anyway, the possibility of non-cognitivist realism is probably not that significant for there being no easy arguments from internalism to anti-realism as long as weakness of will is a problem for the strongest formulations of internalism and there are plenty of internalist cognitivist positions around.

26. Thanks Mike,
    I don’t see the inference that you report, but this might be a matter of interpretation. You say that the following inference is available on your reading of Hume,
    From (1) and (2),
    1. . . . [T]he first species of reasoning [about relations of ideas] alone is [not] ever *the cause* of any action. (my emphasis)
    2. Abstract or demonstrative reasoning. . .never *influences* any of our action ..(also my emphasis)
    To (3),
    3. So Hume’s position is that accepting that 2 is F is not an “action” and hence needs no explanation for how it’s motivated.
    But (3) does not follow from (1) and (2), or not as far as I can see (maybe there’s something implicit here that I’m missing). All that (1) and (2) show (supposing of course that they are true) is that no piece reasoning about relations of ideas *causes or influences* an action. I think I’ve been agreeing with that all along. In any case I’ve meant to be agreeing. My claim has been that accepting that 2 is F is itself an action. I haven’t claimed that accepting that 2 is F causes or influences any action and I haven’t claimed that any piece of reasoning about relations of ideas causes my acceptance that 2 is F. So, as I’ve been urging, it seems that some desire (viz., the desire to act rationally) causes or influences the acceptance that 2 is F.

27. Hi Mike A,
    Not that I see much to recommend the view, but….
    I bet Hume would think of “accepting” the falsity of a proposition as a case of believing something. That is to say he would think it amounts to having a steady, vivacious conception of an idea. I have trouble seeing how the idea of “accepting” a proposition fits into Hume’s system in any other way. But if we take it as having a belief, then I do not see how having such an idea can be said to be an act.
    Moreover, Hume might think that one belief is caused by those preceding it as a result of habit and the resemblance and association of the ideas, instead of being caused by a desire to have ideas that fit some pattern.

28. Yeah, that’s a good point. I’ve been meaning to ask what “accept” a proposition means in this context. If it means “believe” then it is not an action in the relevant sense, plainly.

29. I guess I wouldn’t say “plainly”. For all I know some form of doxastic voluntarism is true. But I mean only that, if I had no desire to act rationally, I would not assent to the proposition that 2 is F. If I did desire to act rationally, I would assent to that proposition. My assenting or not is, I think, an action. People arrested from soliciting drugs, for instance, often do nothing more than assent to a proposition.
    If I took Pascal’s Wager seriously, I would be prepared to assent to propositions for which I know the probability is not greater than even. I choose there, too.

30. That response helps. I think it important in this context to keep the concepts of “acceptance” and “assertion” appart. In your response you seem to be thinking of assertion (The drug case leads me to think that your “assent” is roughly = to assertion)
    But then I have a question. You write: “if I had no desire to act rationally, I would not assent to the proposition that 2 is F.”
    Is this meant as a conceptual claim or an empirical one?
    If empirical, it seems suspect. A tribe could just be habituated to assert their beliefs in certain contexts. Unless you have a weak, dispositional notion of desire AND are thinking of “desire to act rationally” in a mere de re manner, that habituation need not instill a desire to act rationally. Moreover, I am not clear why that tribe is not us. Which brings us to…
    The other line to take here is conceptual – you could claim that a person so habituated does not really count as making assertions (verbally expressing assent) at all. Here I am tempted to shift the burden and ask: If I have a habit to express my beliefs out loud, so to speak, why doesn’t that count as asserting?

31. Brad C., you say
    “The drug case leads me to think that your “assent” is roughly = to assertion”
    I don’t intend assert by ‘assent’. I mean that someone says “want to purchase X” and you assent to the proposition that you would like to purchase X. Similarly for assenting to propositions that conclude arguments of various sorts. You don’t have to make any assertions in these cases.
    You might be unwilling to assent to a proposition that it is practically rational to believe unless it is also theoretically rational to believe it.
    On the other hand you might be unwilling to assent to a proposition for which there is extensive evidence unless it is also practically rational to believe it.
    For a Humean, these decisions are presumably based on an individual’s desires or preferences over practical and theoretical rationality.

32. Hi Mike,
    Just trying to get clear on what acceptance is and whether it is something to which Humeans (or for that matter Aristotelians) are committed.
    To focus, I have a question about your claim that, “people arrested from soliciting drugs, for instance, *often* do *nothing more than* assent to a proposition.” (my emphases)
    This much is true: people often communicate their desire to buy drugs, by uttering some words, making various hand signals, or whatever, and they are arrested on that basis. Very roughly speaking, SOME such outward expression is necessary for the arrest claim to hold up.
    That suggests the following is true: necessarily, A’s assent to “want to purchase this?” involves some outward expression that communicates the desire to purchase. Maybe the necessity claim could be weakened, e.g. to normally, without loosing the explanatory force needed to underwrite the claim about arrests, but that is beside the point.
    I agree that the outward expression that communicates the belief/desire might not ammount to assertion properly speaking, but I do not see how that undercuts the points I made in the pervious post.
    I get the impression that you are thinking of acceptance as, at least, an internal event – a sort of mental endorsement by “the will”. That sounds most un-Humean, so I may be wrong. My main point, however, is to find out if your acceptance has a necessay or normal outward expression as I take your arrest case to suggest.

33. Suppose you provide a version of the ontological argument on the board and finish with conclusion C = There’s a perfect being. Now suppose you say to me: “Ok, if you do not assent to C come to the board and place an ‘N’ next to C.” Under these circumstances, if I show no outward movement whatsoever toward the board and intend thereby to assent to C, then I have assented to C.
    Or, you could do the same thing in your next post and say “Ok, if you do not assent to this conclusion, post something saying so.” Now suppose I understand what you say, and I intentionally follow the rule for assenting by doing nothing at all. That sure seems like assenting to me, though I display no outward motion.

34. Nice! But that does seem to be the odd case in the actual world.
    Imagine I am walking down the street and a guy comes up to me and says, “Hey, want a dime bag? If you just roll your eyes and then keep walking I will assume you want to purchase one.” I just roll my eyes at the clever stoner and keep walking. Now the cops pick me up & say I assented purchasing a dime bag, so they are taking me in.
    To cover these sorts of worries (although I had not thought of these fun cases) I mentioned the retreat from necessary to normal.
    But to extend your to point: A tribe could have a practice of assent where they *always and only* communicate assent by not responding when asked. That practice would get unwieldy – man I would REALLY hate advertising in that world – but it seems conceptually possible.
    The horse may be dead, but: why couldn’t the Humean adopt a “belief coupled with habituated silence” model for that case? The relevant sort of external behavior need only be something amenable to habituation/conditioning, and “doing nothing” counts as external behavior in this sense just as well as our normal ways of comunicating our beleifs.

35. “”doing nothing” counts as external behavior in this sense just as well as our normal ways of comunicating our beleifs.”
    That’s it. I’m crying foul!

36. I had a devil of a time teaching my dog to sit still when I say, “stay”. I had to train him to behave in that fashion. What is so odd about calling that some of his outward behavior?

37. I think Dan Boisvert makes a succinct statement of Putnam’s argument here:
    “He hopes that the “capitulators” in ethics can learn from the “resisters” in philosophy of mathematics by (i) holding onto the claim that ethical statements can be objective and true while (ii) rejecting the claim that ethical statements are objective and true only if there can be objects in the world that “make” them objective and true.”
    I’m not sure how strongly this differs from Blackburn’s quasi-realism, which Putnam seems to reject in the book. I’ve been puzzling over this book for some time, mainly for a (just submitted) review for Essays in Philosophy. This discussion is nice…I wish I’d found it sooner.

38. I just came across a comment by Putnam that I thought might help clarify his opposition to anti-realism in both phil. math and metaethics. It’s from his article “On Wittgenstein’s Philosophy of Mathematics” (Proc. Aris. Soc. Supp. Vol. LXX, 243-264):
    “The problem in all of these cases … is that we wish to impose a pattern of what it is to be true, a pattern devised largely from the successes of the physical sciences, on all of our discourse. … In contrast, the Wittgensteinian strategy, I believe, is to argue that while there is such a thing as correctness in ethics … [and] in mathematics, the way to understand that is not by trying to model it on the ways in which we get things right in physics, but by trying to understand the life we lead with our concepts in each of these distinct areas.” (262-4)
    In reading comments like this, I think it’s understandable to worry (as Eric Rovie does above) that Putnam’s opposition to anti-realists like Blackburn may rest on a misunderstanding. After all, Blackburn himself goes to great lengths to insist that he thinks that (i) there is such a thing as correctness in ethics, and (ii) we will misunderstand what this correctness looks like if we try and model it on what correctness looks like in the physical sciences. But, ultimately, I think this worry is misplaced, because even granting Putnam’s and Blackburn’s shared commitments to (i) and (ii), there remains a deep disagreement between them. The disagreement centers around the question of what resources our philosophical accounts of the different norms governing the physical sciences, ethics, math, etc., are allowed to draw upon. Blackburn is quite clear that a philosophical account of ethics, for instance, must restrict itself to “finding room for ethics, or placing ethics within the disenchanted, non-ethical order which we inhabit” (Ruling Passions, 49). Putnam is not so restrictive, in part because he thinks that accounts that restrict themselves in this respect cannot deliver what they promise.
    To put my own cards on the table: I’m sympathetic to the worries of many (not just Putnam) that philosophical accounts of the different norms governing the physical sciences, ethics, math, etc., that start from a restrictive conception of what there is are ill-equiped to deliver plausible accounts of these norms. But my problem with those who oppose these restrictive accounts is that they themselves tend not to have much to say about what the differences between the norms governing these different areas of inquiry actually consist in. Of course, since many such opponents, like Putnam himself, avow an interest in Wittgenstein, they’ll readily admit that there are such differences. But the effort expended on trying to articulate these differences pales, I think, in comparison to the effort expended by people like Blackburn. And I find that disappointing.
    Sorry for the longish post. I’m interested to hear if other share my sense of the situation.

39. Zed makes some nice points. I found it troubling that Putnam dispenses with Blackburn in a footnote, at least in reference to his quasi-realism. He also chides him for his ‘scientism’ which may explain why his project can’t be Blackburn’s, even if they both end up with objectivity without any moral objects.

40. Thought I would mention that Blackburn has a article on Putnam’s “Collapse” up on his web page: http://www.phil.cam.ac.uk/~swb24/PAPERS/disentangling.pdf