A Reply to Brian Loar's 'Must Beliefs Be Sentences'

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A Reply to Brian Loar's "Must Beliefs Be Sentences?" Jerry Fodor PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association, Vol. 1982, Volume Two: Symposia and Invited Papers. (1982), pp. 644-653. Stable URL: http://links.jstor.org/sici?sici=0270-8647%281982%291982%3C644%3AARTBL%22%3E2.0.CO%3B2-O PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association is currently published by The University of Chicago Press.

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A Reply t o B r i a n L o a r ' s "Must Be1 i e f s Be Sentences?" J e r r y Fodor Massachusetts I n s t i t u t e o f Technology

I n t h e p a r t s o f h i s paper t h a t I ' l l be concerned w i t h here, B r i a n Loar c o n t r a s t s two accounts o f t h e n a t u r e o f b e l i e f s . A c c o r d i n g t o t h e f i r s t , be1 i e f s (and, m u t a t i s mutandi s, o t h e r p r o p o s i t i o n a l a t t i t u d e s ) a r e mental s t a t e s t h a t a r e i n d i v i d u a t e d by r e f e r e n c e t o t h e i r f u n c t i o n a l r o l e (a f u n c t i o n a l r o l e , i n t u r n , i s a p a t t e r n o f causal r e l a t i o n s t h a t a mental s t a t e b e a r s t o a n o r g a n i s m ' s p r o x i m a l i n p u t s and o u t p u t s and t o i t s o t h e r mental s t a t e s ) . A c c o r d i n g t o t h e second account, a b e l i e f i s a r e l a t i o n a l s t a t e o f which t h e r e l a t a a r e , on t h e one hand, t h e organism which e n t e r t a i n s t h e b e l i e f s , and on t h e o t h e r a mental r e p r e s e n t a t i o n . We n e e d n ' t , f o r p r e s e n t purposes, w o r r y much a b o u t what s o r t s o f t h i n g s mental r e p r e s e n t a t i o n s a r e ; f o r o r i e n t a t i o n , t h i n k o f mental p a r t i c u l a r s which serve something l i k e t h e f u n c t i o n t h a t was a s s i g n e d t o " I d e a s " i n c l a s s i c a l e m p i r i c i s t e p i s t e mology. L i k e Ideas, mental r e p r e s e n t a t i o n s a r e supposed t o be possessed s i m u l t a n e o u s l y o f causal and semantic p r o p e r t i e s ; mental r e p r e s e n t a t i o n s a r e t h e r e f o r e s p e c i e s o f symbols. However, mental r e p r e s e n t a t i o n s a r e u n l i k e Ideas i n t h a t t h e y a r e u s u a l l y t a k e n t o be s t r u c t u r e d i n some way analogous t o t h e s t r u c t u r e o f n a t u r a l language sentences. Mental r e p r e s e n t a t i o n s , t h a t i s t o say, a r e supposed t o be species o f d i s c u r s i v e r a t h e r t h a n i c o n i c symbols. I t i s because o f t h i s l a t t e r f e a t u r e o f mental r e p r e s e n t a t i o n t h e o r y t h a t t h e metaphor o f a language o f t h o u g h t seems a p p o s i t e . Loar a p p a r e n t l y t a k e s i t t h a t t h e f u n c t i o n a l r o l e a c c o u n t o f b e l i e f s and t h e mental r e p r e s e n t a t i o n a c c o u n t o f b e l i e f s are, as i t were, f r i e n d l y c o m p e t i t o r s . For though t h e two t h e o r i e s c l e a r l y have a l o t i n common, and though Loar acknowledges t h a t i t c o u l d t u r n o u t t h a t b o t h a r e t r u e , s t i l l he i s i n c l i n e d t o b e l i e v e t h a t t h e arguments f a v o r i n g t h e f u n c t i o r l a l r o l e s t o r y a r e i n b e t t e r shape t h a n t h o s e t h a t f a v o r mental r e p r e s e n t a t i o n s . Indeed, Loar p r e s e n t s a number o f cons i d e r a t i o n s t h a t a r e supposed t o m i l i t a t e f o r t h e f o r m e r as a g a i n s t t h e l a t t e r . By c o n t r a s t , my view (and t h e burden o f my argument i n t h i s commentary) i s t h i s : t h e two accounts are, t o a l l i n t e n t s and

6

PSA 1982, V lume 2, pp. 644-653 1983 by t h e P h i l o s o p h y o f Science A s s o c i a t i o n Copyright

purposes, i n s e p a r a b l e . On t h e one hand, t h e mental r e p r e s e n t a t i o n approach i m p l i c i t l y commits one t o i n d i v i d u a t i n g mental s t a t e s by t h e i r f u n c t i o n a l r o l e s ; and, on t h e o t h e r , i t 1 ' s o n l y by e n d o r s i n g t h e mental r e p r e s e n t a t i o n view t h a t we can make c l e a r how a f u n c t i o n a l r o l e t h e o r y o f p r o p o s i t i o n a l a t t i t u d e s c o u l d be t r u e . Well, t o g e t t o d e t a i l s , L o a r ' s p i c t u r e seems t o be as f o l l o w s : somebody who i s i n t o mental r e p r e s e n t a t i o n s could, a t h i s d i s c r e t i o n , a l s o embrace a f u n c t i o n a l r o l e a c c o u n t o f t h e i v i d u a t i o n o f b e l i e f s . A f t e r a l l , mental r e p r e s e n t a t i o n s a r e supposed t o have causal p r o p e r t i e s , so r e f e r e n c e t o mental r e p r e s e n t a t i o n s m i g h t come i n t o a t h e o r y by way o f answering t h e q u e s t i o n : 'what p r e c i s e l y i s i t t h a t has t h e f u n c t i o n a l r o l e t h a t , a c c o r d i n g t o f u n c t i o n a l r o l e theorists, provides the i n d i v i d u a t i o n condition f o r the b e l i e f t h a t P ? ' Answer: i t i s a c e r t a i n r e l a t i o n a l s t a t e ; v i z . , t h e v e r y r e l a t i o n a l s t a t e whose r e l a t a a r e t h e b e l i e v i n g organism and an approp r i a t e mental s y m b o l ( s eabove). e But, though Loar sees t h a t a a c c e p t t h e view t h a t t h e r e i s mental r e p r e s e n t a t i o n t h e o r i s t some f u n c t i o n a l l y i n d i v i d u a t e d mental s t a t e t h a t a l l and o n l y Pbe1 i e v e r s share (some mental s t a t e w i t h an " i n t e r p e r s o n a l l y a s c r i b a b l e " f u n c t i o n a l r o l e , as L o a r p u t s i t ) , s t i l l he h o l d s t h a t t h i s would be a n excresence on t h e mental r e p r e s e n t a t i o n t h e o r y .

could

What I t a k e i t t h a t Loar has i n m i n d h e r e i s t h a t even i f t h e mental r e p r e s e n t a t i o n t h e o r i s t has t h e o p t i o n o f i n d i v i d u a t i n g b e l i e f s b y t h e i r f u n c t i o n a l r o l e s , s t i l l he a l s o has a n o t h e r o p t i o n ; v i z . , t h a t o f i n d i v i d u a t i n g b e l i e f s by r e f e r e n c e t o t h e c h a r a c t e r o f t h e m e n t a l symbols t h a t t h e organism i s a l l e g e d l y r e l a t e d t o when i t has t h e b e l i e f s . Suppose ( p e r i m p o s s i b l e ) t h a t we t h i n k i n E n g l i s h , so t h a t b e l i e v i n g t h a t i t ' s o i n g t o r a i n i s bearing a c e r t a i n s p e c i f i e d r e l a t i o n ( c a l l i t R*) t o t h e E n g l i s h sentence " i t ' s g o i n g t o r a i n " . Then we can say what i t i s t o have t h e b e l i e f t h a t i t ' s g o i n g t o r a i n w i t h o u t s p e c i f y i n g t h e f u n c t i o n a l r o l e o f t h a t b e l i e f . I n f a c t , we j u s t d i d : i t ' s t o bear R* t o " i t ' s g o i n g t o r a i n " . So t h a t ' s t h e sense i n which Loar t h i n k s t h a t t h e f u n c t i o n a l r o l e s t o r y i s " s t r o n g e r " t h a n t h e mental r e p r e s e n t a t i o n s t o r y : a c c o r d i n g t o t h e former, b u t n o t t h e l a t t e r , b e l i e f - t h a t - i t ' s - g o i n g - t o - r a i n a s c r i p t i o n s i m p l y t h a t t h e r e i s a n i n t e r p e r s o n a l l y shared f u n c t i o n a l r o l e t h a t a l l and o n l y b e l i e f s - t h a t - i t ' s - g o i n g - t o - r a i n have i n common.

I t h i n k , however, t h a t t h i s way o f v i e w i n g t h e s i t u a t i o n i s m i s leading. For i n order t o divorce the i n d i v i d u a t i o n conditions f o r b e l i e f s f r o m t h e s a t i s f a c t i o n o f some i n t e r p e r s o n a l l y a s c r i b a b l e f u n c t i o n a l r o l e , t h e mental r e p r e s e n t a t i o n t h e o r i s t would need t o have a NONFUNCTIONAL c r i t e r i o n f o r t h e t y p e - t o k e n r e l a t i o n f o r mental r e p r e s e n t a t i o n s . Pnd we have n o t g o t such a c r i t e r i o n and, i n my view, i t i s most u n l i k e l y t h a t we a r e g o i n g t o g e t one. Here i s t h e p o i n t i n a n u t s h e l l . Suppose t h a t tokens o f t h e b e l i e f t h a t i t ' s r a i n i n g a r e t o be i d e n t i f i e d w i t h t o k e n i n g s o f t h e f o r m u l a F w h i l e t o k e n s o f t h e b e l i e f t h a t i t ' s snowing a r e t o be i d e n t i f i e d

w i t h t o k e n i n g s o f t h e f o r m u l a G. Then, presumably, we can d i s t i n g u i s h between t h e b e l i e f s i f we can d i s t i n g u i s h between t h e c o r r e s ponding tokens; i n p r i n c i p l e , t h e t y p e l t o k e n r e l a t i o n f o r mental symbols p r o v i d e s a c r i t e r i o n f o r t h e i n d i v i d u a t i o n o f b e l i e f s i f t h e mental r e p r e s e n t a t i o n a c c o u n t o f b e l i e f s i s t r u e . B u t now, how i s t h e t y p e - t o k e n d i s t i n c t i o n f o r mental symbols t o be drawn? Not, p r e sumably, o r t h o g r a p h i c a l l y o r a c o u s t i c a l l y as i n t h e case o f w r i t t e n / spoken t o k e n i n g s o f E n g l i s h sentences. Even i f we t h i n k i n E n g l i s h , t o k e n t h o u g h t s a r e s u r e l y n o t sequences o f graphemes o r phones. So, t h e n , presumably some o t h e r way. I f you a c c e p t t y p e p h y s i c a l i s m , you may suppose t h a t mental r e p r e s e n t a t i o n s o f t h e same ( a s i t were) l i n g u i s t i c t y p e a r e i p s 0 f a c t o p h y s i c a l events o f t h e same n e u r a l t y p e . But few mental r e p r e s e n t a t i o n t h e o r i s t s a c c e p t t y p e p h y s i c a l i s m ; and, even t h o s e who do presumably d o n ' t want t h e t h e o r y o f b e l i e f t o e n t a i l it. T h i s means, so f a r as I can see, t h a t t h e o n l y o p t i o n i s t o assume t h a t t h e t y p e / t o k e n r e l a t i o n f o r mental r e p r e s e n t a t i o n s i s i t s e l f f u n c t i o n a l l y s p e c i f i e d . What makes something a t o k e n o f t h e mental symbol " i t ' s r a i n i n g " i s t h e causal p r o p e r t i e s o f t h e symbol r a t h e r t h a n i t s shape, charge o r b i o c h e m i c a l p e c u l i a r i t i e s . B u t i f t h a t i s t r u e then, i n p r a c t i c e a t l e a s t , t h e mental r e p r e s e n t a t i o n t h e o r i s t i s c o m n i t t e d t o much t h e same c l a i m s a b o u t i n t e r p e r s o n a l f u n c t i o n a l r o l e s as h i s e r s t w h i l e a n t a g o n i s t . So f a r , mental r e p r e s e n t a t i o n t h e o r i s t s and f u n c t i o n a l r o l e t h e o r i s t s l o o k as i f t h e y s i n k o r swim t o g e t h e r . N e v e r t h e l e s s , I agree w i t h Loar t h a t t h e mental r e p r e s e n t a t i o n s t o r y i s i n some sense t h e more adventurous o f t h e two. I n p r i n c i p l e , we c o u l d i d e n t i f y b e l i e f s w i t h s t a t e s t h a t have c h a r a c t e r i s t i c f u n c t i o n a l r o l e s w i t h o u t g o i n g on t o t r y and say, as mental r e p r e s e n t a t i o n t h e o r i s t s do, what t h e (as i t were) i n t e r n a l c o m p o s i t i o n o f such s t a t e s may be. B u t I t h i n k , f o r two reasons, t h a t t h a t would be a bad i d e a . F i r s t , what i s so good a b o u t n o t b e i n g adventurous? It i s h a r d l y t h a t t h e e x c i t e m e n t o f p h i l o s o p h i c a l s p e c u l a t i o n , however venturesome,is l i k e l y t o s t r a i n even a d e l i c a t e nervous s e n s i b i l i t y ; and t h e r e i s t h e Popperian p o i n t t h a t c o n f i r m i n g a s t r o n g h y p o t h e s i s i s ipso f a c t o more i l l u m i n a t i n g t h a n c o n f i r m i n g a weak one. Second, n o t a s k i n g u e s t i o n i s n o t a way o f answering it, and, sooner o r l a t e r , t h e f u n c t i o n a l r o l e t h e o r i s t i s g o i n g t o have t o say something about have t h e f u n c t i o n a l r o l e s t h a t he t a k e s t o what k i n d o f s t a t e s be a p p r o p r i a t e t o t h e i n d i v i d u a t i o n o f be1 i e f s . I f , i n p a r t i c u l a r , no s t a t e s c o u l d have t h e r i g h t causal p r o p e r t i e s , t h e n t h e f u n c t i o n a l r o l e t h e o r i s t i s i n t h e soup. My p o i n t i s t h a t , as t h i n g s stand, t h e r e l a t i o n s - t o - d i s c u r s i v e - s y m b o l s s t o r y i s t h e o n l y p l a u s i b l e one a b o u t what t h e s t r u c t u r e o f such f u n c t i o n a l s t a t e s c o u l d be.

could

LOar L e t me g i v e j u s t one reason why I t h i n k t h a t t h i s i s so. o f f e r s , as one o f t h e prima f a c i e arguments f o r mental r e p r e s e n t a t i o n s , t h e f o l l o w i n g consideration. " B e l i e f s have common s t r u c t u r e s and s t r u c t u r e d r e l a t i o n s t o each o t h e r , f o r example, t h e r e l a t i o n between t h e b e l i e f t h a t q & p and t h e b e l i e f t h a t p , w h i c h a r e essent i a l t o t h e i r r o l e i n psychological explanation. That s t r u c t u r e i s

l a n g u a g e - l i k e ; hence, t h e argument goes, i f i t i s r e a l i z e d t h e r e i s a language o f t h o u g h t . " ( p . 6 3 5 ) . However, L o a r r e p l i e s , we need n o t i n f e r f r o m t h e e x i s t e n c e o f (as i t were) l o g i c a l f o r m i n b e l i e f s t o t h e e x i s t e n c e o f mental symbols. Rather, what a l l c o n j u n c t i v e b e l i e f s ( f o r example) have i n common m i g h t j u s t be " . . . t h e i r conceptual r e l a t i o n s t o o t h e r a p p r o p r i a t e l y indexed b e l i e f s , and n o t ( n e c e s s a r i l y ) t h e i r f i r s t - o r d e r s t r u c t u r e . " ( p . 636). Now, f o r s t a r t e r s , I do n o t t h i n k t h a t " c o n c e p t u a l " r e l a t i o n s t o o t h e r b e l i e f s can be what Loar a c t u a l l y i n t e n d s . For one t h i n g , t h e n o t i o n o f conceptual r e l a t i o n i s u n r e c o n s t r u c t e d i n h i s t h e o r y so i t i s n o t one t o which Loar i s , s t r i c t l y speaking, e n t i t l e d . And, f o r a n o t h e r t h i n g , I suppose t h e conceptual r e l a t i o n s o f a c o n j u n c t i v e b e l i e f would be i d e n t i c a l t o t h o s e o f any l o g i c a l l y e q u i v a l e n t Ec o n j u n c t i v e b e l i e f ; whereas, presumably, one wants a t h e o r y o f p r o p o s i t i o n a l a t t i t u d e t o d i s t i n g u i s h between, say, t h e b e l i e f t h a t P & Q and t h e b e l i e f t h a t ( ( P & -P) V (P & Q ) ) . What L o a r ' s t h e o r y does have t o o f f e r - and what I presume Loar has i n mind - must be t h a t c o n j u n c t i v e ( e t c . ) b e l i e f s have t h e i r conj u n c t i v e structure i n v i r t u e o f t h e i r causal/functional r e l a t i o n t o o t h e r f u n c t i o n a l l y i n d i v i d u a t e d mental s t a t e s . But that r e p l y , though i t i s one L0ar i s i n a p o s i t i o n t o make, r e a l l y misses t h e p o i n t o f t h e problem. The p o i n t o f t h e problem i s t h i s : complex b e l i e f s a r e complex i n a way t h a t c r i e s o u t f o r some e x p l i c a t i o n o f t h e i r s t r u c t u r e i n terms o f c o n s t i t u e n c y r e l a t i o n s . I t l o o k s , t o p u t i t as c r u d e l y as p o s s i b l e , as though t h e b e l i e f t h a t P & Q ought t o have something P - i s h and something Q - i s h as i t s c o n s t i t u e n t s ; and t h e q u e s t i o n i s what on e a r t h t h e s e P - i s h and Q - i s h t h i n g s m i g h t be:

- n o t t h e p r o p o s i t i o n s P and Q s i n c e , on t h e s o r t o f " n a t u r a l i s t i c " t h e o r y t h a t Loar and I b o t h have i n mind, r e f e r e n c e t o p r o p o s i t i o n s must be e l i m i n a b l e i n t h e l o n g r u n .

- n o t t h e b e l i e f t h a t P and t h e b e l i e f t h a t Q because t h e analogous s o l u t i o n w i l l n o t work f o r t h e c o n s t i t u e n t s o f t h e b e l i e f t h a t P v Q . T h a t i s , s i n c e you can have t h e b e l i e f t h a t P v Q and n o t have e i t h e r t h e b e l i e f t h a t P o r t h e b e l i e f t h a t Q, i t cannot be t h a t t h e l a t t e r b e l i e f s are c o n s t i t u e n t s o f t h e former.

-

- f o r s i m i l a r reasons, i t seems t h a t you cannot c o n s t r u e t h e cons t i t u e n t s o f a b e l i e f as c o n s t i t u e n t s o f i t s f u n c t i o n a l r o l e . Suppose t h a t t h e r e i s a f u n c t i o n a l r o l e C t h e possession o f which i s what i n d i v i d u a t e s t h e b e l i e f t h a t P v Q. I t cannot be ( o r , a t l e a s t , i t cann o t be i n any way t h a t I can make o u t ) t h a t C has as constituents the functional r o l e s associated (respectively) w i t h the b e l i e f t h a t P and t h e b e l i e f t h a t Q. A f t e r a l l , f u n c t i o n a l r o l e s a r e j u s t causal powers, and i t ' s n o t , t o p u t i t m i l d l y , o b v i o u s t h a t t h e r e need be a n y t h i n g t h a t h a v i n g t h e b e l i e f t h a t P v Q causes one t o t h i n k o r do t h a t i s i d e n t i f i a b l y l i k e what h a v i n g t h e b e l i e f t h a t P o r t h e b e l i e f

t h a t Q causes one t o t h i n k o r do. And, even i f t h e r e i s some such i d e n t i f i a b l e causal r o l e c o n s t i t u e n t i n t h e case o f r e l a t i v e l y s i m p l e d i s j u n c t i v e b e l i e f s , t h i n k o f a l l t h e o t h e r ( a l l t h e i n f i n i t e 1 many c o n s t i t u e n t s . Dies one o t h e r ) b e l i e f s t h a t also have P - i s h an-sh r e a l l y want t o u n d e r t a k e t h e burden o f showing t h a t t h e causal r o l e o f , say, t h e b e l i e f t h a t ( i f P t h e n Q ( t h e n i f P t h e n Q o r R ) ) ) has t h e causal r o l e s of P, Q, and R as i t s c o n s t i t u e n t s ? I, f o r one, would n o t know where t o b e g i n . Whereas, i t i s one o f t h e l o v e l y t h i n g s a b o u t t h e language o f t h o u g h t s t o r y t h a t i t g i v e s you t h e c o n s t i t u e n t r e l a t i o n you want f o r free. S p e c i f i c a l l y , i t i s j u s t a c o n d i t i o n upon t h e c o n s t r u c t i o n o f a t y p e / t o k e n r e l a t i o n f o r mental r e p r e s e n t a t i o n s t h a t t o k e n i n g s o f t h e mental symbol t h a t serves as t h e o b j e c t (as i t were) o f t h e b e l i e f t h a t P v Q s h o u l d ( l i t e r a l l y ) c o n t a i n t o k e n i n g s o f whatever mental symbol serves as t h e o b j e c t o f t h e l i e f t h a t P and o f whatever mental symbol serves as t h e o b j e c t o f t h e b e l i e f t h a t Q. J u s t as t o k e n i n s c r i p t i o n s o f t h e f o r m u l a "P v Q" c o n t a i n as l i t e r a l p a r t s t o k e n i n s c r i p t i o n s o f t h e f o r m u l a "P" and o f t h e f o r m u l a "Q". D i g r e s s i o n : you m i g h t suppose t h a t t h e m e n t a l - r e p r e s e n t a t i o n - a s constituent story actually e n t a i l s the causal-role-as-constituent s t o r y , and t h e r e b y i n h e r i t s t h e disadvantages o f t h e l a t t e r . For, y o u m i g h t argue, i f tokens o f t h e mental f o r m u l a s f o r P and f o r Q a r e a c t u a l l y p a r t s o f t h e mental f o r m u l a f o r P v Q, and i f t h e causal r o l e o f a mental s t a t e i s s e n s i t i v e t o t h e c o n s t i t u e n c y o f t h e f o r m u l a t h a t i s tokened when one i s i n t h a t s t a t e (as, indeed, i t must be i f what one contemplates i s some f o r m o f com u t a t i o n a l psychology) t h e n i s i t not g o i n g t o t u r n o u t t h a t t h e cauv Q has t h e causal r o l e o f Q as a c o n s t i t u e n t r e c i s e l y because t h e mental symbol f o r P v Q has t h e mental symbol $ o r Q as a c o n s t i t u e n t ? Answer: o f course n o t . The e f f e c t s o f a mental t o k e n i n g o f P v Q need no more c o n t a i n t h e e f f e c t s o f a mental t o k e n i n g o f P t h a n t h e e f f e c t s o f r e a d i n g t h a t , say, i f i t snows i n August t h e n t h e r e w i l l b e a h e a t wave i n December need i n c l u d e t h e e f f e c t s o f r e a d i n g t h a t i t w i l l snow i n August. I n f a c t , j u s t as i t i s p r e e m i n e n t l y a v i r t u e o f mental r e p r e s e n t a t i o n psychology t h a t i t p e r m i t s us t o c o - o p t t h e l i n g u i s t i c n o t i o n o f cons t i t u e n c y f o r o u r account o f t h e s t r u c t u r e o f mental s t a t e s , so i t i s p r e e m i n e n t l y a v i r t u e o f mental r e p r e s e n t a t i o n t h e o r y t h a t i t a l l o w s us t o c o - o p t l o g i c and computer t h e o r y f o r o u r account o f t h e n a t u r e o f mental rocesses. A f t e r a l l , l o g i c shows us e x a c t l y how t o use t h e syntacDic c o n s t i t u e n c y o f t h e f o r m u l a "P v Q" t o determine t h e e n t a i l m e n t s o f t h e p r o p o s i t i o n t h a t t h a t f o r m u l a expresses. And comp u t e r t h e o r y shows us how t o b u i l d symbol h a n d l i n g mechanisms whose causal processes r e s p e c t , i n a p p r o p r i a t e ways, t h e i n f e r e n t i a l r e l a t i o n s i m p l i c i t i n t h e s y n t a c t i c c o n s t i t u e n c y o f l i n g u i s t i c formulas. Once a g a i n : psychology g e t s a l l t h i s t h e o r y f o r f r e e i f i t once buys t h e mental r e p r e s e n t a t i o n s t o r y .

So what I c l a i m i s t h i s : we need a t h e o r y o f mental s t a t e s ( l i k e be1 i e f s ) and o f mental processes (1 i k e drawing i n f e r e n c e s ) . I t l o o k s as though n o t i o n s o f s t r u c t u r e , and s p e c i f i c a l l y o f c o n s t i t u e n c y , must

be a t t h e h e a r t o f b o t h t h e o r i e s s i n c e , t o p u t i t r o u g h l y , i t i s i n v i r t u e o f t h e i r c o n s t i t u e n c y t h a t (complex) mental s t a t e s have t h e i r semantic p r o p e r t i e s and t h e i r causal r o l e s . The l i n g u i s t i c n o t i o n o f c o n s t i t u e n c y , imp1 i c i t i n t h e p o s t u l a t i o n o f mental symbols, appears t o g i v e us j u s t what we need; i t a l l o w s us t o ground o u r a c c o u n t o f t h e semantics o f mental r e p r e s e n t a t i o n s i n l o g i c and t o ground o u r a c c o u n t o f t h e causal p r o p e r t i e s o f mental r e p r e s e n t a t i o n s i n computer t h e o r y . Moreover, t h e r e a r e l i t e r a l l y no competing accounts. Take away t h e l i n g u i s t i c n o t i o n o f c o n s t i t u e n c y , and we have no i d e a a t a l l o f how b e l i e f s c o u l d have t h e i r i n f e r e n t i a l l i a s o n s o r t h e i r causal roles. Loar m i g h t w i s h t o r e p l y t h a t o n l y t h e u n e l a b o r a t e d causal r o l e s t o r y c o u n t s as " e x p l i c a t i o n " o f b e l i e f , b u t I am n o t s u r e what t h i s amounts t o o r why one s h o u l d c a r e . S u r e l y n e i t h e r t h e o r y p r o v i d e s a n " a n a l y s i s " (as one used t o s a y ) o f t h e " o r d i n a r y n o t i o n " (as one a l s o used t o say) o f b e l i e f . Nor do I r e a l l y t h i n k t h a t h u n t i n g f o r analyses ( i n t h a t , o r maybe any o t h e r , sense) i s a r e a s o n a b l e o c c u p a t i o n f o r grown-ups. What we do want, o r so i t seems t o me, i s My p o i n t has been t h a t j u s t a w o r k a b l e t h e o r y a b o u t what b e l i e f s i f t h e mental r e p r e s e n t a t i o n s t o r y does n o t p r o v i d e t h e t h e o r y , i t i s u n l i k e l y t h a t any o t h e r k i n d o f f u n c t i o n a l i s m w i l l do so e i t h e r .

are.

I w i l l s t o p p r e t t y soon, I promise. B u t f i r s t , l e t me say j u s t a l i t t l e a b o u t some o f t h e p o i n t s LOar makes towards t h e end o f h i s paper a b o u t how t o r u n a t h e o r y o f t h e t r u t h c o n d i t i o n s o f b e l i e f s . As we have seen, t h e n a t u r a l move f o r a r e p r e s e n t a t i o n a l i s t i s t o assume t h a t mental symbols have a l a n g u a g e - l i k e c o n s t i t u e n t s t r u c t u r e and t h e n t o use more o r l e s s f a m i l i a r l o g i c a l d e v i c e s t o e x p l a i n how t h e semantic p r o p e r t i e s o f complex mental symbols a r e i n h e r i t e d f r o m t h e semantic p r o p e r t i e s o f t h e i r a t o m i c c o n s t i t u e n t s . But, n o t o r i o u s l y , that s o r t o f t h e o r y says n o t h i n g a b o u t how mental r e p r e s e n t a t i o n s g e t a t t a c h e d t o t h e w o r l d (how, f o r example, t h e y have ' e x t e r n a l ' t r u t h c o n d i t i o n s as w e l l as ' i n t e r n a l ' causal r o l e s ) and somet h i n g does v e r y much need t o be s a i d a b o u t t h a t q u e s t i o n . There i s a r e c e n t , p r o f o u n d l y unpublished, paper o f mine which s e t s o u t what Loar c a l l s an " i d e a l i n d i c a t i o n t h e o r y " . T h i s i s a l o n g , complicated business, b u t the basic idea i s t h a t t h e t r u t h c o n d i t i o n o f a mental r e p r e s e n t a t i o n i s t h a t s t a t e o f a f f a i r s which would cause a t o k e n i n g o f t h e mental r e p r e s e n t a t i o n under i d e a l c o n d i t i o n s o f t r a n s p a r e n c y o f evidence.

I t h i n k I l i k e t h i s i d e a l a r g e l y because i t seems so v e r y implausi b l e . For example, as Loar p o i n t s o u t , and as I emphasize i n my paper, i t e n t a i l s t h a t any organism t h a t has b e l i e f s a t a l l i s omnis c i e n t under a p p r o p r i a t e i d e a l i z a t i o n . I n f a c t , t o p u t t h e p o i n t more s t r o n g l y , t h e whole i d e a i s b u i l t on t h e i n s i g h t t h a t omniscience i s , as you m i g h t say, t h e t h e o r e t i c a l l y p e r s p i c u o u s c o n d i t i o n f o r a n a c c o u n t o f t h e semantics o f m e n t a l r e p r e s e n t a t i o n s . Consider God. There i s no problem a b o u t what makes a c e r t a i n s t a t e o f a f f a i r s t h e t r u t h c o n d i t i o n o f one o f H i s m e n t a l r e p r e s e n t a t i o n s . Since God b e l i e v e s a l l and o n l y t h e t r u t h s , H i s mental r e p r e s e n t a t i o n s g e t

tokened when, and o n l y when, t h e i r t r u t h c o n d i t i o n s a r e s a t i s f i e d . The t r u t h c o n d i t i o n s o f H i s mental r e p r e s e n t a t i o n s can t h u s be i d e n t i f i e d w i t h whatever s t a t e s o f a f f a i r s a r e c a u s a l l y necessary and s u f f i c i e n t f o r t h e i r tokenings. T h i s may sound p r e t t y s i l l y i n i t s s h o r t v e r s i o n ( a c t u a l l y , i t sounds p r e t t y s i l l y i n i t s l o n g v e r s i o n , t o o ) . But I f i n d i t s o r t o f grows on you a f t e r a w h i l e ; a t a minimum I t h i n k I can show t h a t y o u have t o accept i t i f you a r e g o i n g t o a p p l y t o t h e case o f mental r e p r e s e n t a t i o n t h e s o r t o f " i n f o r m a t i o n a l " semantics t h a t p h i l o s o p h e r s l i k e Stampe and D r e t s k e have r e c e n t l y been f r u i t f u l l y e x p l o r i n g . I w o n ' t , however, t r y t o c o n v i n c e you o f t h i s here. S u f f i c e i t t o say t h a t I do n o t t h i n k t h a t t h e s o r t s o f o b j e c t i o n s Loar r a i s e s f o r t h e program a r e anywhere near d e c i s i v e . F i r s t , Loar says, "The i d e a l i n d i c a t i o n t h e o r y r e q u i r e s t h a t e v e r y i n n e r sentence ... i s i n d i v i d u a l l y s e n s i t i v e t o i t s t r u t h c o n d i t i o n ... But t h i s a p p a r e n t l y c o n f l i c t s w i t h a r a t h e r b a s i c i d e a about t r u t h c o n d i t i o n s , namely, t h a t t h e t r u t h - c o n d i t i o n o f a new sentence i s der i v a t i v e from t h e i n d e e n d e n t l y c o n s t i t u t e d semantic p r o p e r t i e s o f i t s c o n s t i t u e n t s . " ( p . 638P. B u t t h i s i s j u s t wrong i f i t i s supposed t o suggest t h a t t h e f a c t t h a t , f o r example, t h e mental symbol "P 81 Q" has t h e t r u t h c o n d i t i o n s t h a t i t does i s somehow independent o f t h e f a c t t h a t t h e mental symbol "P" has t h e t r u t h c o n d i t i o n t h a t does. On t h e c o n t r a r y , as we have j u s t seen, mental r e p r e s e n t a t i o n t h e o r y appeals t o i n t e r f o r m u l a i c r e l a t i o n s among mental r e p r e s e n t a t i o n s p r e c i s e l y as t h e v e h i c l e f o r p r o j e c t i n g t h e semantics o f i n d e f i n i t e l y many complex b e l i e f s f r o m t h e semantics o f a presumably f i n i t e p r i m i t i v e b a s i s . The b e s t way t o l o o k a t t h i s i s t o t h i n k o f t h e c o g n i t i v e ( i .e., b e l i e f - f i x i n g ) mechanisms o f an organism as a p h y s i c a l r e a l i z a t i o n o f a f u n c t i o n f r o m s t a t e s o f a f f a i r s o n t o mental r e p r e s e n t a t i o n s . Under a p p r o p r i a t e i d e a l i z a t i o n , t h e range and domain o f t h i s f u n c t i o n a r e b o t h i n f i n i t e . I n e f f e c t , t h e system has an i n f i n i t y o f d i s p o s i t i o n a l p r o p e r t i e s o f t h e form: t o k e n t h e mental r e p r e s e n t a t i o n The c o m p u t a t i o n a l s t r u c t u r e of r iff the state o f a f f a i r s ?obtains. t h i s system i s o f p r e c i s e l y t h e s o r t f a m i l i a r f r o m t r u t h d e f i n i t i o n s f o r f o r m a l languages. So t h a t , f o r example, t h e f a c t t h a t t h e d e v i c e tokens "P & Q" i f f i t i s t h e case t h a t P and t h e case t h a t Q i s connected, i n a s t r a i g h t f o r w a r d way, w i t h t h e f a c t t h a t t h e d e v i c e tokens "P" i f f i t i s t h e case t h a t P and tokens "Q" i f f i t i s t h e case t h a t Q. Under t h e o p e r a t i v e i d e a l i z a t i o n , and g i v e n t h e r u l e s f o r "&", t h e causal c o n d i t i o n s f o r t o k e n i n g "P & Q" a r e s a t i s f i e d by, and o n l y by, t h e s a t i s f a c t i o n o f t h e causal c o n d i t i o n s f o r t o k e n i n g "P" and t h e s a t i s f a c t i o n o f t h e causal c o n d i t i o n s f o r t o k e n i n g " Q " . Nothing could be f u r t h e r f r o m t h e i d e a t h a t "every i n n e r sentence i s i n d i v i d u a l l y s e n s i t i v e " t o i t s t r u t h c o n d i t i o n ; and, i n f a c t , I do n o t see how t o make sense o f t h a t i d e a f o r any c o g n i t i v e system o f which t h e r e p r e s e n t a t i o n a l c a p a c i t i e s a r e i n f i n i t e ( a s t h e y s u r e l y a r e f o r us and, I suppose, f o r any d e v i c e w i t h a r e m o t e l y i n t e r e s t i n g mental l i f e ) . L o a r ' s second o b j e c t i o n i s t h a t "some t h e o r i e s t h a t we a c c e p t emerged as hypotheses f r o m t h e i d i o s y n c r a t i c a b i l it i e s . . . o f c r e a t i v e

i n d i v i d u a l s . T h a t t h e r e i s a method t h a t i s t h e n a t u r a l endowment o f each o f us, and t h a t c o u l d have generated t h o s e hypotheses, i s a n i n t e r e s t i n g b u t f a r from obvious t h e s i s . " (p.638). But t h i s o b j e c t i o n i s misled; the ideal i n d i c a t i o n theory i s , i n a c e r t a i n attenuated - o r anyhow i t need n o t be sense, v e r i f i c a t i o n i s t ; b u t i t i s o p e r a t i o n i s t . I t has t o assume, t h a t i s t o say, t h a t e v e r y c o g n i z i n g organism ends toward omniscience i n t h e l i m i t ; t h a t t h e p r o b a b i l i t y t h a t one b e l i e v e s t h a t P becomes a r b i t r a r i l y c l o s e t o u n i t y as t h e evidence t h a t P becomes a r b i t r a r i l y t r a n s p a r e n t . B u t t h i s does n o t e n t a i l t h a t t h e r e must be a n y t h i n g l i k e a method o r procedure f o r d e t e r m i n i n g whether i t i s t h e case t h a t P s i n c e t h e r e i s , i n g e n e r a l , no method o r procedure f o r b r i n g i n g i t about t h a t evidence becomes a r b i t r a r i l y transparent. F i n a l l y , i t seems t o me f a l s e t h a t t h e i d e a l i n d i c a t o r t h e o r y i s incompatible w i t h realism; o r a t least, i f i t i s , the brain-in-a-vat c o n s i d e r a t i o n s do n o t seem t o me t o show t h a t i t i s . What t h e t h e o r y r e q u i r e s , once again, i s omniscience i n t h e e v i d e n t i a l l i m i t ; i n e f f e c t , t h a t i f we a r e b r a i n s i n a v a t , t h e n t h e p r o b a b i l i t y t h a t we w i l l come t o b e l i e v e t h a t we a r e w i l l i n c r e a s e a r b i t r a r i l y as t h e evidence t h a t we a r e b r a i n s i n a v a t g e t s a r b i t r a r i l y b e t t e r . But, o f course, i f t h e b r a i n i n a v a t s t o r y i s a c t u a l l y t r u e o f us now, t h e n t h e e v i d e n t i a l c o n d i t i o n i s e g r e g i o u s l y not s a t i s f i e d . Things l o o k t o us v e r y much as though we a r e n o t b r a i n s i n a v a t b u t r a t h e r c r e a t u r e s i n a w o r l d . I t a k e i t t h a t nobody d e n i e s t h a t t h a t i s t h e s t a t e o f t h e evidence we have, even i f one a c c e p t s t h e l o g i c a l p o s s i b i l i t y t h a t t h e e v i d e n c e we have i s s y s t e m a t i c a l l y m i s l e a d i n g . So now l e t us l o o k a t L o a r ' s argument. Supposing t h a t I am a b r a i n i n a v a t , t h e r e i s , Loar says, "no doubt ...a p o s s i b l e t r u t h t h e o r e t i c i n t e r p r e t a t i o n o f my b e l i e f s which makes them about my sense-data and r e n d e r s them l a r g e l y t r u e on t h a t i n t e r p r e t a t i o n . " (p. 6 4 0 ) . L e t us c a l l t h a t i n t e r p r e t a t i o n Then B r i a n ' s p o i n t i s t h a t s i n c e t h e i d e a l i n d i c a t o r t h e o r y r e q u i r e s us t o a c c e p t t h e i n t e r p r e t a t i o n o f o u r mental s t a t e s t h a t maximizes t h e i r t r u t h o v e r - a l l , t h e n I must be t h e r i g h t i n t e r p r e t a t i o n o f my c u r r e n t b e l i e f s . B u t t h i s i s supposed t o show t h a t t h e i d e a l i n d i c a t o r t h e o r y must be wrong s i n c e , s u r e l y , i f I am a b r a i n i n a v a t , t h e n almost e v e r y t h i n g I now b e l i e v e is

I.

false.

I t s h o u l d now be e v i d e n t w h a t ' s wrong w i t h t h i s ; s i m p l y t h a t t h e i d e a l i n d i c a t i o n t h e o r y does n o t r e q u i r e t h a t t h e r i q h t i n t e r p r e t a t i o n f o r my b e l i e f s i s t h e o n e X i i c f i a x i m i z e s t r u t h h e r e and now. What i t r e q u i r e i s t h a t y o u maximize t r u t h i n t h e e v i d e n t i a l l i m i t . And t h e s a t i s f a c t i o n o f t h i s l a t t e r requirement i s e n t i r e l y compatible w i t h as t h e i n t e r p r e t a t i o n scheme f o r my b e l i e f s even though rejecting i s t h e i n t e r p r e t a t i o n scheme which would maximize t r u t h i f my e v i d e n t i a l s i t u a t i o n were as b e n i g h t e d as t h a t o f a b r a i n i n a v a t . To r e p e a t : t h e i d e a l i n d i c a t o r t h e o r y does n o t say ' p i c k t h e i n t e r p r e t a t i o n scheme t h a t maximizes t r u t h come what may'; what i t says i s o n l y ' p i c k t h e i n t e r p r e t a t i o n scheme which maximizes t r u t h i n c i r c u m stances where t h e t r u t h i s what t h e organism has e v e r y r e a s o n t o

does

I

b e l i e v e ' . I n my view, t h e i r f a i l u r e t o observe t h i s d i s t i n c t i o n has been a s e r i o u s d e f e c t i n p r e v i o u s f o r m u l a t i o n s o f " p r i n c i p l e s o f charity". As f o r t h e more g e n e r a l i s s u e s about t h e r e l a t i o n s between r e a l i s m and t h e i d e a l i n d i c a t o r t h e o r y , t h e y r e q u i r e a l o t more s o r t i n g o u t t h a n I have room f o r here. But r o u g h l y , i f what r e a l i s m r e q u i r e s i s t h a t we understand t r u t h n o n e p i s t e m i c a l l y , as correspondence w i t h states o f a f f a i r s , then t h e i d e a l i n d i c a t o r theory i s thoroughly r e a l i s t i c . The e p i s t e m i c c o n s i d e r a t i o n s come i n , n o t i n s a y i n g what t r u t h i s , b u t o n l y i n d e c i d i n g which s t a t e o f a f f a i r s a mental symbol c o r r e i t i s t r u e ; v i z . , t h a t s t a t e o f a f f a i r s which would sponds t o cause t h e t o k e n i n g o f t h e symbol under c o n d i t i o n s o f i d e a l e v i d e n t i a l transparency .

if

There i s , f o r a l l t h a t , p l e n t y t o w o r r y about w i t h i d e a l i n d i c a t o r t h e o r i e s . For one t h i n g , t h e y a r e a species o f v e r i f i c a t i o n i s m . As such t h e y i m p l y , as B r i a n c o r r e c t l y n o t e s , t h a t t h e r e a r e e p i s t e m i c n o t f a i l t o b e l i e v e t h e t r u e . And circumstances i n which we though t h i s c l a i m i s a t t e n u a t e d i n p r o p o r t i o n as t h e circumstances a r e i d e a l i z e d , I w i l l n o t blame you i f even a t t e n u a t e d v e r i f i c a t i o n i s m i s more t h a n you a r e prepared t o swallow. So perhaps I had b e t t e r c l o s e by emphasizing t h a t t h e need f o r an account o f how mental s t a t e s g e t a t t a c h e d t o t h e i r t r u t h c o n d i t i o n s i s n o t p r o p r i e t a r y t o mental r e p r e s e n t a t i o n c o n s t r u a l s o f p r o p o s i t i o n a l a t t i t u d e s . L e t b e l i e f s and d e s i r e s be c o n s t r u e d as f u n c t i o n a l s t a t e s . SO l o n g as 'causal r o l e s ' a r e r e l a t i o n s t o p r o x i m a l e v e n t s l i k e sensory i n p u t s and motor o u t p u t s , t h e q u e s t i o n must be f a c e d as t o what r e l a t e s p r o p o s i t i o n a l a t t i t u d e s t o d i s t a l events including, notably, t h e s a t i s f a c t i o n o f t h e i r t r u t h c o n d i t i o n s . F u n c t i o n a l i s m does n o t , I r e p e a t , g e t you o u t o f t h i s . The problem i s i m p l i c i t i n any due r e c o g n i t i o n t h a t p r o p o s i t i o n a l a t t i tudes have semantic p r o p e r t i e s l i k e t r u t h and f a l s i t y . So, t o p u t i t b r i e f l y , I would 1 i k e t h e i d e a l i n d i c a t o r s t o r y t o pan o u t i f o n l y because i t i s so whacky. But, i f i t does n o t , a l l o f us m e n t a l i s t s w i l l have t o go h u n t i n g f o r an a l t e r n a t i v e s t o r y ; and we w i l l a l l have t o go h u n t i n g f o r i t t o g e t h e r .

could

Loar, Brian. (1983). "Must B e l i e f s Be S e n t e n c e s ? " I n pSA 1 9 8 7 Volume 2. Edited by P e t e r D. A s q u i t h and Thomas N i c k l e s . East Lansing, Michigan: P h i l o s o p h y o f S c i e n c e A s s o c i a t i o n . Pages 627-643.