In Reason, Truth and History, Hilary Putnam presentsan argument aimed at showing that the modern sceptic hypothesis of brains in a vatis self-refuting. In my view, and despite the enormous amount of literatura about this argument, it has not yet been shown all the absurd consequences to which the assumption of the tesis thatPutnam maintains in order to refute that hypothesis may lead.The purpose of this paper is then to explore to the last consecuentes that argument and, bringing to light its scarce plausibility, to cast serious doubt upon Putnam's strategy.