Ruby said WT don't teach that the spirit is a force?
Jws literally believe that god made Adams body out of clay and then infused it with an ethereal force called spirit. What could possibly be more irrational or anti scientific?
JWs certainly believe in the supernatural but it is a matter of degree. There is a spectrum from mysticism to rationalism. The reformation, for example, is widely interpreted as being a step away from mysticism, and toward rationalism, as was the adoption of monotheism two millennia previously. Protestants still believed in the Bible and the supernatural, but they got rid of saints and icons and a lot of the mythical aspects that had grown up. At the extreme rational end of the mythical to rational spectrum you've got Unitarians.
No one is saying JWs deny the supernatural. But they are definitely toward the rational rather than the mystical end of the spectrum. They believe that reality can be understood by rational deduction and reading the Bible, not by mystical experiences or pilgrimages or miraculous occurrences.