The Metaphysics of Thought: A Response to Fish and Macdonald

Abstract

John McDowell’s position on the metaphysics of thought combines an identity conception of truth, the view that if one thinks truly that p, then what one thinks is the fact that p, with a Tractarian conception of the world as the totality of facts. In response to the charge that it is incoherent, William Fish and Cynthia Macdonald have recently (2007, 2009, 2011) defended a novel way of developing McDowell’s position. I argue that their interesting proposal doesn't work, owing to the fact that it can accommodate neither false thought nor, it seems, certain cases of true thought.     

Partial reinforcement effects and type of reward

In two experiments 68 rats were trained to bar press or run down a straight runway for food or for water under conditions of either continuous reinforcement or partial reinforcement. In both experiments, there was greater persistence of behavior which had been reinforced with food than with water. In Expt 2, the partial reinforcement extinction effect (PREE) was observed with food reward, but not with water.Within the context of the experimental procedures used, it can be concluded that the rat has mechanisms for developing persistence which are dependent on the specific motivational system involved. This conclusion is related to theories of partial reinforcement effects and to possible biological origins of the mechanisms.