can readily  be uncovered  by examining  the typical
　　   Nyaaya inference scheme. Of the notion that a Nyaaya
　　   scheme   could  be  a   "formalistic   explanation"
　　   without  being an inference, I shall say very little
　　   because I do not see how anything which functions as
　　   an explanation  could not involve inferences of some
　　   kind or other.  It is important  to know whether the
　　   Nyaaya  scheme  is deductive  or not, and  if it is,
　　   whether  all  of its  parts  are  essential  to  the
　　   deduction.  I will demonstrate  that  there  are two
　　   ways  of  reading  the  Nyaaya  form: one  which  is
　　   straightforwardly  deductive  and a second  which is
　　   best  understood  by what  the American  pragmatist,
　　   C.S.　　 Peirce,   and　　 later　　 Norwood　　 Hanson,
　　   call "retroduction."

　　　　  To  begin  with,  consider  this  representative
　　   example from the Nyaaya:(5)

　　　　  1. pak.sa (thesis) Sound is imprrmanrne

　　　　  2. hetu (mark  or  Reason)  -   Because  of  its
　　　　　　 property of being produced

　　　　　　　　　　　　  P.184

　　　　  3.  d.r.s.taanta  (Exemplification)--Whatever is
　　　　　　 produced, is impermanent
　　　　  4.  sapak.sa (similar case)-  As with a pot, and
　　　　　　 so forth
　　　　  5.  vipak.sa (dissimilar case)- As (not with the
　　　　　　 case) of space, and so forth

　　　　  Tachikawa proposes the following scheme for what
　　   he calls the "three-membered Indian syllogism:(6)

　　　　  6.  There is property p in locus L
　　　　  7.  (because) there is property q (in L).
　　　　  8.  Wherever  there  is  property  q,  there  is
　　　　　　 property p, as in locus w

　　   Clearly, if this  schema  is  reversed, (8) and  (7)
　　   become premises for a valid deductive  inference  of
　　   (6) as the conclusion.  The reverse  of our  example
　　   becomes an instance of modus ponens.

　　　　  9.  d.r.s.taanta   -   Whatever  is  created  is
　　　　　　 impermanent.
　　　　  10. hetu - Sound is created.
　　　　  11. pak.sa - Sound is impermanent.

　　　　  Why is this instance of modus ponens a matter of
　　   dispute? The incompatibilists  point  out  that  the