ABSTRACT
P la to has now show n th a t i n s o f a r a s T h e a e t e tu s 1 d e f in i t io n of
know ledge a s p e r c e p t io n c o in c id e s w ith and d ra w s s u p p o r t f r o m the P r o
ta g o r e a n d o c t r in e of m a n the m e a s u r e , i t i s not a c c e p ta b le . A s soon a s
P r o t a g o r e a n i s m is ex tended beyond th e ju d g m e n ts w h ich ea c h m a n
m a k e s ab o u t the s e n s e - c o n te n t s a c tu a l ly p r e s e n t to h is c o n s c io u s n e s s
a t the t im e of sp e a k in g (179c 1 -4 ) , and m a d e to app ly to ju d g m e n ts
about fu tu r e e v e n ts , w h a t is a d v a n ta g e o u s , e tc . , i t i s qu i te c e r t a in ly a
f a l s e d o c t r in e . P r o t a g o r e a n i s m , a s a d i s t in c t iv e th e o ry , m u s t be r e j e c t
ed. If any p a r t of i t i s to be r e t a in e d i t w i l l be i t s a p p l ic a t io n to ju d g
m e n ts of im m e d ia t e s e n s e - p e r c e p t io n (cf. 171e 1-3). But, now th a t a s
a g e n e r a l d o c t r in e P r o t a g o r e a n i s m h a s b een re fu te d , im m e d ia t e s e n s e
p e r c e p t io n m u s t be e x am in ed on i t s own g round to s e e w h e th e r i t i s
a lw ays t r u e and w h e th e r i t s ju d g m e n ts a r e a lw ay s known to be t r u e . If
i t t u r n s out th a t they a r e known, th en to th is e x ten t P r o t a g o r e a n i s m w i l l
have b e e n v in d ic a te d ; but one can n o t any lo n g e r r e a s o n in the o th e r
d i r e c t io n an d u s e P r o t a g o r e a n i s m to v in d ic a te s e n s e - p e r c e p t i o n 1 s c l a im
to be know ledge .
