Abstract

Bas van Fraassen has presented a most vigorous argument in support of an anti-realist interpretation of science. In defence of his view he revives the seemingly moribund 'observable-unobservable' distinction, and employs it in the attempt to show that science provides no grounds for accepting, as real, entities which it itself classifies as unobservable. Traditional arguments against the observable-unobservable distinction can be reinterpreted as arguments for the reality of what is unobservable to humans. The argument is quite straightforward. We could create intelligent creatures with a perceptual range of observation superior to that of humans. Granted that they are intelligent, we would accept them into the epistemic community. Once accepted their pronouncements should become belief-worthy for us. The aim of the paper is to defend this argument against van Fraassen 's seemingly plausible charge that, roughly, it fallaciously assumes that we ought to admit merely possible evidence rather than actual evidence in the formation of our beliefs