ABSTRACT
In the ex p o s i t io n of the th e o ry of p e r c e p t io n and the d i s c u s s io n s
a s s o c i a t e d w ith i t P ro ta g o ra s * d o c t r in e abou t t r u th has been g rounded
in the flux th e o ry so f a r a s i t s im p l ic a t io n s fo r T heaete tus* v iew s on
know ledge a r e c o n c e rn e d . H is th e o ry th a t w hat s e e m s to be the c a s e
( t o ^ a t v o ^ v t v ) to each p e r s o n is the c a s e fo r h im has been
tak^.i (152c 1 - 3 ) to im p ly th a t w h a t a p p e a r s to each p e r s o n in p e r c e p t io n
is t r u e fo r h im who p e r c e iv e s i t , on the g round tha t in the c a s e of p e r
cep tu a l p r o p e r t i e s s e e m in g to be, e. g. , r e d am o u n ts to being p e r c e iv e d
a s r e d (152b 11). T he flux th e o ry w as then b ro u g h t in and d eve loped a s
a m e a n s of defending h is v iew in i t s a p p l ic a t io n to p e rc e p t io n and p e r
cep tu a l ju d g m e n ts . But of c o u r s e P r o t a g o r a s m e a n t to be upholding a
u n iv e r s a l th e s i s abou t t r u t h and w ish e d to a s s e r t th a t w h a te v e r a p e r s o n
m ig h t m a k e ( s in c e re ly ) an a s s e r t i o n abou t he n e c e s s a r i l y sa id so m e th in g
t r u e about i t - - a s . ru e , th a t i s , a s any th ing anyone could ev e r a s s e r t .
