Alan,
Thanks for your explanation. Two things puzzle me however:
1) I thought there was a difference culturally between Jawa and the island of Java (including Sunda)? Your sources seem to be Jawanese and based on Kejawen. The Swedish anthropologist refers to specific Sundanese belief systems and Sundanese informants. Silat practitioners or not is in this case irrelevant as far as they were familiar with the Sundanese culture.
2) Of course the information is based on our current belief systems. The same are historical "facts" and historical "logic" and belief systems. All present historical research is based on an understanding that presumes our current belief systems. And so are your Jawanese informants' opinions and also all yours and mine logical arguments and evidence. Unfortunately that is a "logical fact" that none of us can ignore.
But let us agree on your last sentence and leave the theory of science to the philosophers...