That's interesting. I hadn't thought of synaesthesia. However, this statement --

"Rather than assuming that people give off auras or energy fields that can only be detected by rigged cameras or trained seers, we need only assume that the phenomenon of synaesthesia is taking place."

-- seems to assume there are a whole lot of synaesthetics around.

Synaesthesia doubtless explains some aura sightings, but assuming that it explains all is not exactly scientific.

Bogus reductionism turns science into just another belief system. Carl Sagan for one made some pretty fanciful explanations that I think did science no service.

clint