Have you ever wondered why there is such variance as to the number of pramanas? Some say one, some say 2 and and others three and six. Surely we ought to know how many ‘hands’ we have. As possibly a result of the creeping force of the illative I’ve lately begun to notice the different translations for pramana generally as ‘valid means of knowledge’ or ‘valid means of cognition’. Therein may lie the core of variance.
Knowledge it seems to me is part of the established mental store. This is the stuff we are sure of and this very right to claim knowledge is the entry point of the sceptical wedge. This has been the focus of discussion about 'justified true belief’ , Moore’s paradox and so forth. Now Indian epistemology has focused on empirical rules of thumb as it were, which are sound ways of getting to the point where you might claim knowledge but yet prescind from certainly as to whether it is. For example you were using a valid means of cognition or cognising normally when you spotted a coin. However when you bent to pick it up it was only a piece of silver paper. Knowledge evaded you for the moment in one respect but in another you now know that it was just silver paper. A lose/win situation sort of.
Is the reduction of the number of pramanas to just two, perception and inference, the result of two forms of apphension viz. physical and mental. We grasp the particular in the physical and abstract the universal mentally. There seems a basic robust modesty about this view unlil we consider that an important element of the definition of pramana is that it is a means of knowledge that cannot be reduced to any other. Ignoring that is to change the conversation.
Ethan Mills has a note on Dignaga's view: