Doxastic Desire Douglas Campbell Department of Philosophy There
× Doxastic Desire Douglas Campbell Department of Philosophy
There are lots of attitudes • For any given proposition, p, one might – believe that p, – desire that p – be sorry that p – imagine that p – be excited that p – doubt that p – grimly suspect that p – Etc…
Some attitudes are reducible to others (or to combinations of other attitudes and their causal relations to each other and to other things) 1. One thinks that p iff one believes that p. 2. One wants that p iff one desires that p. 3. One wishes that p iff one desires that p but believes that p is unlikely. 4. One fears that p iff one desires that p but believes that ¬p is possible, and this beliefdesire combination causes a feeling of fear. 5. Etc…
How many attitudes are there at the level of reductive bedrock? My two-part view: 1. Desire As Belief: desires are reducible to beliefs. – I. e. , to have a desire is to have a corresponding belief. – Also endorsed by Humberstone (1987), Mc. Naughton (1988) and Gregory (forthcoming). 2. Attitudinal monism: there is only one irreducible attitude, belief.
Why do Desire As Belief and Attitudinal Monism matter? Desire as Belief supports solves Smith’s Moral Problem produces Improvements In theoretical economy helps solve The problem of naturalizing propositional attitudes Attitudinal Monism
The ‘moral problem’ Motivational Humeanism • MH 1: An agent can be motivated to act only by some combination of a desire and a means-end belief • MH 2: Desires and beliefs are ‘distinct existences’ in the sense that they are modally separable. Internalism: moral judgements, when combined with suitable means-end beliefs, have motivational force. Cognitivism: moral judgments are judgments about matters of fact. × Moral judgements are desires If a moral judgement is a desire, then it is not a belief, and vice versa Moral judgements are beliefs
How Attitudinal Monism helps solve the problem of naturalizing the propositional attitudes The problem decomposes into two sub-problems: • Propositional sub-problem. For any given proposition p, what are the naturalistic properties of the brain in virtue of which it mentally grasps p? • Attitudinal sub-problem. For any given attitude, A, what are the naturalistic properties of the brain in virtue of which it grasps propositions under the aegis of A instead of some other attitude?
Suppose there were five fundamental attitudes—A, B, C, D and E. • A solution to the attitudinal sub-problem would then need to include a five-way decision procedure for classifying any given grasping of p as being a token of one of the following five propositional attitudes: Ap, Bp, Cp, Dp or Ep.
Suppose instead that there were only two fundamental attitudes—belief and desire. • A solution to the attitudinal sub-problem would then only need to include a binary decision procedure, for classifying a grasping of p as being either a belief that p or a desire that p.
Finally, imagine Attitudinal Monism is true. There is only one fundamental attitude, belief • A decision procedure that must always yield the same answer—‘belief’—is no real decision procedure at all, there being no decision to be made. • So the attitudinal sub-problem is thereby reduced to triviality, and dissolved.
• This still leaves the other half of the problem of naturalizing propositional attitudes—the propositional half—intact. • But progress can be claimed even on this front. – A satisfactory solution to the propositional subproblem is liable to be much easier to find when it needn’t be compatible with a separate solution to the attitudinal sub-problem.
Plan 1. Describe the Doxastic Theory of Desire (DTD) 2. Explain how DTD avoids common objections to Desire as Belief Theories 3. Explain how DTD improves on other Desire as Belief Theories 4. Q&A
The traditional belief-desire theory of means-end rationality Homer strongly desires that [1]. He also believes that [2]. (1) I drink beer. (2) If I get off the couch and go to the fridge, then [I drink beer] will become true. Lo: Homer gets off the couch and goes to the fridge. Why? Because his practical reasoning system instantiates both these rules: • MER 1 (means-end rule, version 1): if one desires, with strength x, that , and if one believes that by -ing one will make it the case that , then one has a motivating reason, of strength x, to . • MAX (maximising rule): if one has motivating reasons to that are collectively stronger than one’s motivating reasons for performing other actions incompatible with , then one is to ).
DTD, part 1. How can a belief motivate? • I introduce a special concept, the D concept. It is a twoplace predicate that accepts a proposition and a scalar value as arguments. • Homer believes both [2] and [3]: (2) If I get off the couch and go to the fridge, then [I drink beer] will become true. (3) D([I drink beer], 100) • His practical reasoning system instantiates both MAX and MER 2: Means-end rule, version 2 (MER 2): if one believes that D( , x) and that by -ing she will make it the case that , then one has a motivating reason, of strength x, to .
The D concept is functionally characterized • Any concept that has the same functional role as the D concept vis-à-vis motivation is the D concept. • The D concept is intrinsically motivationally “pushy”.
DTD, part 2. What is a desire? • RED: An agent desires that with strength x iff she believes that D( , x). • If animals or infants have desires, RED implies that they also have D-beliefs. • DTD therefore implies that the D concept is phylogenetically and ontogenetically primal. • D is to instrumental rationality (and thus to practical rationality) rather as concepts like negation and entailment are to theoretical rationality—utterly fundamental.
In reducing desires to D-beliefs, RED also reduces MER 1 to MER 2 • MER 1 (means-end rule, version 1): if one desires, with strength x, that , and if one believes that by -ing one will make it the case that , then one has a motivating reason, of strength x, to . • Means-end rule, version 2 (MER 2): if one believes that D( , x) and that by -ing she will make it the case that , then one has a motivating reason, of strength x, to . • So RED implies that we can explain Homer’s trip to the fridge in either of two equivalent ways: 1. 2. By citing his means-end beliefs, desires and MER 1. By citing his means-end beliefs, D-beliefs and MER 2.
DTD, part 3. What does D( , x) mean? What are its truth conditions? • Imagine D([I drink beer], 100) was truthconditionally equivalent to [snow is white]. • This would be absurd! – Show Homer lots of white snow, and if he is theoretically rational he will start desiring to drink beer! – Show Homer some green snow, and his desire for beer should be extinguished.
• A theory about the meaning of the D-concept can be plausible only if it identifies the truthconditions of D( , x) with conditions under which it would be appropriate for an agent to desire that with a strength of x. • The task of analysing D’s truth-conditional content therefore devolves directly into the task of developing a general, normative theory of desire—a theory capable of telling us, for any and x, the conditions under which an agent should desire that with a strength of x.
One possibility: Motivational Hedonism • Bentham: ‘Nature has placed mankind under the governance of two sovereign masters, pain, and pleasure. It is for them alone to point out what we ought to do, as well as to determine what we shall do. ’ • Locke: ‘For whatsoever good is proposed, if its absence carries no displeasure or pain with it, if a man be easy and content without it, there is no desire of it, nor endeavour after it. ’ • Hume: ‘’Tis obvious, that when we have the prospect of pain or pleasure from any object, we feel a consequent emotion of aversion or propensity, and are carry’d to avoid or embrace what will give us this uneasiness or satisfaction…. ’Tis from the prospect of pain or pleasure that the aversion or propensity arises towards any object…’
• Hedonistic Theory of Desirability (HTD): D( , x) is true iff one would experience a net total of x units of pleasure (positive) and pain (negative) were to be the case
Another possibility: Kant’s categorical imperative. • Kantian Theory of Desirability (KTD): D( , x) is true iff a rationally perfect system of universal laws would prescribe, rather than proscribe, agents being motivated, with a strength of x, to make it the case that is true.
DTD is neutral with regards D’s truthconditions • DTD is intended to consistent with HTD, KTD, or any other normative theory of desire. • But even while remaining neutral between theories, I think it is safe to tentatively endorse the following, deliberately equivocal theory: Generic Theory of Desirability (GTD): D( , x) is true iff ’s being the case would be valuable (i. e. , good, or morally right, or attractive, or pleasurable, or desirable, or utilityinducing, well-being-inducing, or eudemonia-inducing, or happiness-inducing) to degree x.
DTD, part 4: D is intensional • The ‘Clark Kent’ and ‘Superman’ concepts are intensional siblings. They have the same extension but different intensions.
• DTD includes the idea that D may have one or more intensional siblings. • If E is an intensional sibling of D, then D( , x) and E( , x) will be truth-conditionally equivalent. – They will amount to two ways of saying the same thing: namely, that is valuable to degree x. • But because only the D concept engages MER 2, only Dbeliefs will be motivationally forceful, and only Dbeliefs will be identical to desires. • To believe that E( , x) will be to believe that is valuable to degree x in a way that does not produce a corresponding desire.
The unwilling addict • An addict strongly desires to take heroin, but believes that taking heroin to be very bad, not good. What is going on here? • There is (we may suppose) a mismatch between what she D-believes and what she E-believes. – She believes that D([I take heroin], 1000), thus having an overwhelmingly powerful desire to take heroin. – At the same time believes that E([I take heroin], -500), thus believing taking heroin to be of very great ‘disvalue’. – So she is powerfully motivated to take the drug despite knowing full well she oughtn’t take it.
The depressive • A depressive believes that her trying to get a job would be very good. Yet she is listless and lacks any corresponding motivation to try to get a job. What is going on? • Again, we can posit a mismatch between what is D-believed and what is E-believed. – She believes that E([I try to get a job], 100), and so believes going job hunting to be ‘valuable’. – However she doesn’t have the corresponding motivationally forceful belief that D([I try to get a job], 100), and so doesn’t desire to go job hunting.
The amoralist • An amoralist is an expert where moral facts are concerned. • She knows as well as anyone that her being kind to others is ‘valuable’. But because she is amoral, she has no corresponding desire or motivation to be kind to others. – She believes that E([I am kind to others], 100), but not that D([I am kind to others], 100). – So she lacks the desire and motivation to be kind.
DTD, part 5: D-beliefs are sometimes unruly • Definition: beliefs are unruly if they refuse to pop into existence or pop out of existence at the behest and command of theoretical rationality.
Examples of unruly belief: 1. Certain perceptual beliefs • E. g. , Ebbinghaus illusion:
Count the black dots.
Examples of unruly belief: 2. Racist and sexist prejudices • The Implicit Association Test (Greenwald, Mc. Ghee, and Schwartz 1998) reveals racist and sexist prejudices in most people. • Knowing you have these prejudices is of next to no help in eliminating them.
Examples of unruly belief: 3. Aliefs • The prospective bungy jumper believes that jumping is perfectly safe, but at the same time alieves that it is dangerous (Gendler, 2008). The irrational alief contends powerfully with the rationally accredited belief, so that the jumper struggles to jump.
A way of curing heroin addiction? • Imagine we teach the addict that D and E are intensional siblings. • She is now in a position to infer, from her knowledge that D([I take heroin], -500) is true, that D([I take heroin], -500) is also true, and thus also infer that D([I take heroin], 1000) is false. • So she should stop believing that D([I take heroin], 1000). • Her desire should be extinguished and her addiction cured. • But this obviously won’t work in practice!
The unruliness of desire and of Dbeliefs • Why can’t heroin addiction be cured by conceptual analysis? • Because “Desires … do not come and go at our behest”. “They are not under the direct control of the will” (Mc. Naughton , 1988, p. 125). • In short desires are unruly. • DTD explains the unruliness of desire in terms of the unruliness of the D-beliefs they are identical to. • The addict’s addiction is thereby explained on the same model as, say, the Ebbinghaus illusion.
It appears plausible that evolution has hardwired many unruly D-beliefs into us. • D-beliefs that ground innate desires for: – food, – sex, – survival, – the well-being of our children, – social esteem, – etc. …
Summary DTD is theory there are D-beliefs with these 5 properties: 1. D-beliefs are motivationally forceful due to the operation of MER 2. 2. D-beliefs are identical to desires (RED). 3. To believe that D(�� , x) is, roughly, to believe that �� ’s being true would be valuable to degree x. 4. D-beliefs are intensional. 5. D-beliefs suffer a tendency to unruliness.
1 st Objection to Desire As Belief: Modal Seperability • DWB (desire without belief). It is possible to desire that without believing that D( , x). – E. g. , The addict, who desires to take heroin without believing it valuable to take heroin. • BWD (belief without desire). It is possible to believe that D( , x) without desiring that . – E. g. , The depressive, who believes that hunting for a job is valuable but does not desire to hunt for a job.
Reply (preempted above) • DTD explains cases like the addict and depressive in terms of the intensionality and unruliness of D-beliefs.
2 nd Objection to Desire As Belief: Michael Smith’s ‘directions of fit’ argument • When an agent’s beliefs don’t ‘fit’ (i. e. , accurately represent) the states of affairs that obtain in the world, she should correct the discrepancy by making suitable adjustments to the beliefs in question. • In contrast, when her desires don’t ‘fit’ the states of affairs that obtain in the world, she should correct the discrepancy by initiating bodily actions that will change the states of affairs. • The two directions of fit clash: – Suppose R has both directions of fit, and it doesn’t fit the world. – Then it should both change to fit the world, and remain unchanged while causing the agent to change the world. Contradiction!
Reply (as per Mc. Dowell 1978; Pettit 1987; Mc. Naughton 1988; Price 1989; Little 1997; Tenenbaum 2006; Bromwich 2010; Kriegel 2012; Park 2013) • The clash disappears if a desire and the belief it is identical to have different contents. • Homer believes that D([I drink beer], 100) • He therefore has both these dispositions: – To make it the case that [I drink beer] is true. – To retract the belief and desire if he acquires evidence that drinking beer is not valuable to degree 100. – There is no contradiction.
3 rd Objection to Desire As Belief: Nick Zangwill’s argument from motivational force • Zangwill: – Suppose agents A and B are both equally certain that taking bribes is ‘bad’. – Then they should be equally motivated not to take bribes. – But it is conceivable that A will take the bribe while B won’t. • My reply: – A might be certain that D([I take bribes], -100) is true while B might be equally certain that D([I take bribes], -200) is true. – This explains why they can be differently motivated despite being equally certain that taking bribes is bad. – They disagree about how bad it is.
4 th Objection to Desire As Belief: Neil Sinhanabu’s argument from theoretical economy • Sinhanabu’s theory (in ‘Humean Nature’, forthcoming): 1. Motivationally forceful Desires 2. Cause pleasure/pain as subjective probability of being satisfied rises/falls 3. Help direct attention Beliefs 4. Do 1— 3 with force proportional to vividness of desired object.
My reply Plus: 1. Motivationally forceful 1. The DTD enables us to save both Cause pleasure/pain D-beliefs internalism and 2. cognitivism; and: as subjective =Desires probability of being satisfied rises/falls 2. By supporting Attitudinal Monism, DTD supports the dissolution of direct the attention 3. Help Other Beliefs attitudinal sub-problem and thereby 4. Do 1— 3 of with force proportional helps solve the problem naturalizing vividness of desired object. the propositional to attitudes. Theoretical reasoning system 5. Sometimes unruly
Rival Desire-as-Belief theories 1. Humberstone (1987): For an agent to desire that is for her to believe that D , where D means roughly ‘it is desirable that ’ or ‘would that it were that ’, but with the D-concept’s precise content is left open. 2. Mc. Naughton (1988, 112): For an agent to desire that is for her to believe ’s being true is attractive. 3. Alex Gregory (forthcoming): For an agent to desire to ϕ is for her to believe she has normative reason to ϕ.
DTD’s advantages over rival Desire-as. Belief theories Major: 1. It provides better explanation of apparent cases of modal separability (the addict, depressive, amoralist, etc. …) in terms of intensionality and unruliness. – Humberstone (1987): doesn’t deal with modal separability. – Mc. Naughton (1988): alludes to the unruliness of desire in explaining the addict case. But does not explain it in terms of unruly belief, or mention intensionality. – Gregory (forthcoming): posits a mismatch between the strength of a desire and its motivational force. This is arguably incoherent.
DTD’s advantages over rival Desire-as. Belief theories Minor: 2. Explains how infants and animals can have desires, in terms of the innateness and phylogenetic ancientness of the D concept. 3. Makes explicit allowance for desires coming in different degrees of strength.
Questions!!!
- Slides: 48