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.

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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 . Accord ing 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 - tudes) 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 re fe rence 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 bears t o an organ ism's prox imal i n p u t s and ou tpu ts and t o i t s o t h e r mental s t a t e s ) . Accord ing 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 are , 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 needn ' t , f o r p resen t purposes, wor ry much about what s o r t s o f t h i n g s mental r ep resen ta t i ons are ; 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 ass igned t o " Ideas" i n c l a s s i c a l e m p i r i c i s t ep i s te - 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 pos- sessed s imu l taneous l y o f causal and semant ic 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 spec ies o f symbols. However, mental r e p r e - sen ta t i ons 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 taken 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 ep resen ta t i ons , 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 than 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 thought seems appos i t e .

Loar appa ren t l y takes i t t h a t t h e f u n c t i o n a l r o l e account 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 account o f b e l i e f s are, as i t were, f r i e n d l y compe 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 bo th 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 those 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 presents a number o f con- s 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 he fo rmer 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

PSA 1982, V lume 2, pp. 644-653 Copyr igh t 6 1983 by t h e Ph i losophy o f Science A s s o c i a t i o n

purposes, i nsepa rab le . 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 endors ing t h e mental r e p r e s e n t a t i o n v iew 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 .

Wel l , 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 account 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 ep resen ta t i ons 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 ques t i on : '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 , acco rd ing t o f u n c t i o n a l r o l e t h e o r i s t s , p rov ides t h e i n d i v i d u a t i o n c o n d i t i o n f o r t he 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 he b e l i e v i n g organism and an appro- p r i a t e mental s y m b o l ( s e eabove). But, though Loar sees t h a t a mental r e p r e s e n t a t i o n t h e o r i s t could accept t h e v iew t h a t t h e r e i s 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 P- be1 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 Loar pu ts i t ) , s t i l l he ho lds t h a t t h i s would be an excresence on t h e mental r e p r e s e n t a t i o n t heo ry .

What I t a k e i t t h a t Loar has i n mind here 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 by 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 another 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 re fe rence t o t h e c h a r a c t e r o f t h e menta 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 (pe r imposs ib le ) t h a t we t h i n k i n Eng l ish , 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 bea r i ng 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 go ing 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 go ing 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 go ing 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 han t h e mental r e p r e s e n t a t i o n s t o r y : acco rd ing 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 imp ly t h a t t h e r e i s an 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 ew ing t h e s i t u a t i o n i s m is - l e a d i n g . For i n o r d e r t o d i v o r c e t h e i n d i v i d u a t i o n c o n d i t i o n s f o r b e l i e f s f rom 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 func- 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 ype - token r e l a t i o n f o r mental r e p r e -sen ta t i ons . 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 go ing 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 token ings o f t h e f o rmu la F w h i l e tokens 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 token ings o f t h e fo rmula G. Then, presumably, we can d i s t i n - gu i sh 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 rov ides 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 account o f b e l i e f s i s t r u e . But now, how i s t h e type- token d i s t i n c t i o n f o r mental symbols t o be drawn? Not, p re -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 token ings o f E n g l i s h sentences. Even i f we t h i n k i n Eng l i sh , token thoughts a r e s u r e l y n o t sequences o f graphemes o r phones. So, then, presumably some o t h e r way. I f you accept t ype phys ica l ism, 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 (as 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 phys i ca l events o f t h e same neu ra l t ype . 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 accept t ype phys i ca l i sm; and, even those who do presumably d o n ' t want t h e t heo ry 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 ype / token r e l a t i o n f o r mental r ep resen ta t i ons 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 token 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 he symbol r a t h e r than i t s shape, charge o r b iochemica l p e c u l i a r i t i e s . But 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 comn i t t ed t o much t h e same c la ims about 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 they s i n k o r swim toge the r .

Never the less , 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 unc - t i o n a l r o l e s w i t h o u t go ing 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 compos i t ion o f such s t a t e s may be. But I t h i n k , f o r two reasons, t h a t t h a t would be a bad i dea . F i r s t , what i s so good about n o t be ing adventurous? It i s h a r d l y t h a t t h e exc i tement o f p h i l o s o p h i c a l specu la t i on , however ven- turesome,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 Popper ian 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 hypo thes i s i s ipso f a c t o more i l l u m i n a t i n g than 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 go ing t o have t o say something about what k i n d o f s t a t e s could have t h e f u n c t i o n a l r o l e s t h a t he takes t o 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 hen 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 re la t i ons - to -d i scu rs i ve -symbo ls s t o r y i s t h e o n l y p l a u s i b l e one about 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 cou ld be.

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. LOar 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 ep resen ta - 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 the 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 , wh ich a r e essen- t i a l t o t h e i r r o l e i n psycho log i ca l exp lana t i on . That s t r u c t u r e i s

l anguage - l i ke ; 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 hough t . " ( p . 635 ) . However, Loar r e p l i e s , we need n o t i n f e r f rom t h e ex i s tence o f (as i t were) l o g i c a l fo rm i n b e l i e f s t o t h e ex i s tence 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 igh 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 be 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 "conceptua 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 tends . 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 un recons t ruc ted 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 another 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 those o f any l o g i c a l l y e q u i v a l e n t E-c 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 ropos 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 con-j u n c t i v e s t r u c t u r e i n v i r t u e o f t h e i r c a u s a l / f u n c t i o n a l 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 . It looks, t o pu t i t as c r u d e l y as poss ib le , as though t h e b e l i e f t h a t P & Q ought t o have something P - i sh 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 ques t i on i s what on e a r t h these P - i sh and Q - i s h t h i n g s m igh t be:

- n o t t h e p r o p o s i t i o n s P and Q s ince, 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, re fe rence 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 run .

- 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. That i s , s i nce 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 a r e c o n s t i t u e n t s o f t h e fo rmer .

- f o r s i m i l a r reasons, i t seems t h a t you cannot const rue t h e con- s 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. It cannot be (o r , a t l e a s t , i t can-n o t be i n any way t h a t I can make o u t ) t h a t C has as -c o n s t i t u e n t s t h e f u n c t i o n a l r o l e s assoc ia ted ( r e s p e c t i v e l y ) w i t h 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. 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 no t , t o p u t i t m i l d l y , obv ious t h a t t h e r e need be a n y t h i n g t h a t hav ing 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 hav ing 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 imple 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 manyo t h e r ) b e l i e f s t h a t also have P- ish an-sh c o n s t i t u e n t s . Dies one r e a l l y want t o under take 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 hen Q ( t h e n i f P then 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 beg in .

Whereas, i t i s one o f t h e l o v e l y t h i n g s about t h e language o f thought 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 f ree . 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 type/ token r e l a t i o n f o r mental r ep resen ta t i ons t h a t token ings 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 shou ld ( l i t e r a l l y ) c o n t a i n token ings 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 token i n s c r i p t i o n s o f t h e fo rmula "P v Q" c o n t a i n as l i t e r a l p a r t s token i n s c r i p t i o n s o f t h e fo rmula "P" and o f t h e fo rmula "Q".

D ig ress ion : you m igh t suppose t h a t t h e menta l - representa t ion-as-c o n s t i t u e n t s t o r y a c t u a l l y e n t a i l s t h e c a u s a l - r o l e - a s - c o n s t i t u e n t s t o r y , and thereby i n h e r i t s t h e disadvantages o f t h e l a t t e r . For, you m igh t argue, i f tokens o f t h e mental fo rmulas 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 fo rmula 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 cons t i t uency o f t h e f o rmu la 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 form o f com u t a t i o n a l psychology) t hen i s i t not go ing t o t u r n ou t t h a t t h e cau- v 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 $or 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 oken ing 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 oken ing o f P than t h e e f f e c t s o f r ead ing 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 be a hea 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 ead ing 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 preeminent ly 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 pe rm i t s us t o co-opt t h e l i n g u i s t i c n o t i o n o f con- s t i t u e n c y f o r ou r account o f t h e s t r u c t u r e o f mental s ta tes , so i t i s preeminent ly 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 ows us t o co-opt l o g i c and computer t h e o r y f o r ou 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 cons t i t uency o f t h e f o rmu la "P v Q" t o determine t h e en ta i lmen ts o f t h e p r o p o s i t i o n t h a t t h a t fo rmula expresses. And com- p u t e r t h e o r y shows us how t o b u i l d symbol hand l i ng mechanisms whose causal processes respec 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 cons t i t uency o f l i n g u i s t i c formulas. Once aga in : psychology ge ts 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 ) . It l o o k s as though no t i ons 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 cons t i t uency , must

be a t t h e h e a r t o f bo th t h e o r i e s s ince, t o p u t i t rough 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 semant ic 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 cons t i t uency , 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 account 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 account 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 heo ry . 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 cons t i t uency , and we have no i dea 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 r o l e s . Loar m i g h t w ish t o r e p l y t h a t o n l y t h e une labora ted causal r o l e s t o r y counts 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 sure what t h i s amounts t o o r why one shou ld care . Su re l y n e i t h e r t h e o r y p ro - v i d e s an " a n a l y s i s " (as one used t o say) 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 the r , sense) i s a reasonab le occupa t i on f o r grown-ups. What we do want, o r so i t seems t o me, i s j u s t a workab le t heo ry about what b e l i e f s are. My p o i n t has been t h a t 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 theory , 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 .

I w i l l s top 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 about 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 about 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 anguage - l i ke c o n s t i t u e n t s t r u c t u r e and then 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 dev ices t o e x p l a i n how t h e semant ic 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 rom t h e semantic p r o p e r t i e s o f t h e i r a tomic c o n s t i t u e n t s . But, n o t o r i -ous l y , that s o r t o f t h e o r y says n o t h i n g about how mental r ep resen ta -t i o n s g e t a t t a c h e d t o t he w o r l d (how, f o r example, they have ' ex - 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 some- t h i n g does v e r y much need t o be s a i d about t h a t ques t i on .

There i s a recen t , p ro found l y unpubl ished, 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 " . Th i s i s a long, compl ica ted bus iness, b u t t h e b a s i c i dea 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 oken ing 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 ransparency o f evidence.

I t h i n k I l i k e t h i s i dea l a r g e l y because i t seems so v e r y implaus- i b l e . For example, as Loar p o i n t s ou 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 omni- s 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 dea 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 persp icuous c o n d i t i o n f o r an account o f t h e semant ics o f menta l r e p r e s e n t a t i o n s . Consider God. There i s no problem about 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 menta 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 ep resen ta t i ons can thus be i den - 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 token ings.

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 ve rs ion , 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 wh i l e ; a t a minimum I t h i n k I can show t h a t you have t o accept i t i f you a r e go ing t o app 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 ph i l osophe rs l i k e Stampe and Dretske 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 won ' t , however, t r y t o conv ince 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 heo ry r e q u i r e s t h a t eve ry 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 appa ren 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 dea 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 de- r i v a t i v e from t h e i nde enden 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. But 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 con t ra ry , 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 ep resen ta t i ons p re - 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 rom 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 bes 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 phys i ca l r e a l -i z a t i o n o f a f u n c t i o n f rom s t a t e s o f a f f a i r s on to mental r ep resen ta - 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 bo th 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 oken t h e mental r e p r e s e n t a t i o n -r i f f t h e s t a t e o f a f f a i r s ? o b t a i n s . The computa t iona l s t r u c t u r e of 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 rom t r u t h d e f i n i t i o n s f o r fo rmal languages. So t h a t , f o r example, t h e f a c t t h a t t h e dev ice 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 con- nected, 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 dev i ce 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 oken ing "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 oken ing "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 oken ing " Q " . Noth ing c o u l d be f u r t h e r f rom t h e i dea 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 dea f o r any c o g n i t i v e system o f which t h e rep re - 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 (as t h e y s u r e l y a r e f o r us and, I suppose, f o r any dev i ce w i t h a remo te 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 accept emerged as hypotheses f rom 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 . That 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 those hypotheses, i s an i n t e r e s t i n g b u t f a r f rom obv ious t h e s i s . " ( p .638 ) . But t h i s o b j e c t i o n i s m is led ; t h e i d e a l i n d i c a t i o n t h e o r y i s , i n a c e r t a i n a t t e n u a t e d sense, v e r i f i c a t i o n i s t ; b u t i t i s - o r anyhow i t need n o t be -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 eve ry cogn i z i ng 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 be l i eves 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 anspa ren t . But 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 any th ing l i k e a method o r procedure f o r de te rm in ing whether i t i s t h e case t h a t P s i nce t h e r e i s , i n genera 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 t r anspa ren t .

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 i ncompa t i b l e w i t h rea l i sm; o r a t l e a s t , i f i t i s , t h e b r a i n - i n - a - v a t cons ide ra t i ons 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 va t , then 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 nc rease 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 ge ts 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 hen the 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 ook 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 rea tu res i n a wor ld . I t a k e i t t h a t nobody den ies 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 accepts 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 ev idence we have i s s y s t e m a t i c a l l y m is lead ing .

So now l e t us l ook a t L o a r ' s argument. Supposing t h a t I am a b r a i n i n a va 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 renders 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. 640) . 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 I. 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 heo ry r e q u i r e s us t o accept t h e i n t e r p r e - t a t i o n o f ou 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 , then Imust 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 . Bu 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 ince, su re l y , i f I am a b r a i n i n a va t , then almost e v e r y t h i n g I now b e l i e v e i s false.

I t shou ld now be e v i d e n t w h a t ' s wrong w i t h t h i s ; s imply 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 here and now. What i t does r e q u i r e i s t h a t you 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 requ i rement i s e n t i r e l y compat ib le w i t h r e j e c t i n g 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 I 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 ev i - d e n t i a l s i t u a t i o n were as ben ighted as t h a t o f a b r a i n i n a v a t . To repea t : t h e i d e a l i n d i c a t o r t heo ry 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 rcum- stances where t h e t r u t h i s what t h e organism has eve ry reason t o

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 se r i ous d e f e c t i n p rev ious 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 c h a r i t y " .

As f o r t h e more genera l i ssues 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 heo ry , t hey r e q u i r e a l o t more s o r t i n g o u t t han I have room f o r here. But rough 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 nonep i s tem ica l l y , as correspondence w i t h s t a t e s 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 t heo ry i s t ho rough l y r e a l - i s t i c . The ep i s tem ic cons ide ra t i ons come i n , n o t i n say ing 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 -sponds t o if 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 cause t h e token ing 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 t ransparency .

There i s , f o r a l l t h a t , p l e n t y t o wo 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 hey 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 imply , as B r i a n c o r r e c t l y notes , t h a t t h e r e a r e ep i s tem ic c i rcumstances i n which we could n o t f a i l t o b e l i e v e the t r u e . And though t h i s c l a i m i s a t t enua ted i n p r o p o r t i o n as t h e c i rcumstances 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 enua ted v e r i f i c a t i o n i s m i s more than you a r e prepared t o swal low. So perhaps I had b e t t e r c l o s e by emphasiz ing 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 ached 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 des i res be const rued as f u n c t i o n a l s ta tes . 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 rox ima l events l i k e sensory i n p u t s and motor ou tpu ts , t h e ques t i on must be faced 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 i n c l u d i n g , no tab l y , 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 . Func t i ona l i sm does no t , I repeat , 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 , Iwould 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 no 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 toge the r .

Loar , B r i a n . ( 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 Pe te r D. Asqui th and Thomas Nick les . E a s t Lansing, Michigan: Ph i losophy o f S c i e n c e A s s o c i a t i o n . Pages 627-643.