“…pragmatism is perhaps the worst idea that philosophy ever had” says recently deceased philosopher, Jerry Fodor. Not only is it bad, but according to Fodor it is false, and necessarily so.
Pragmatism suggests that rationalists have got it all the wrong way round. Instead of having thoughts about the world, we make plans in it. We can believe in the existence of material objects because belief in material objects is indispensable for science and science is what we want to do in the world. The problem is that it is impossible to put the cart before the horse. Whichever way one sets it up, being committed to the truth value of a proposition is always prior to everything else. Fodor puts it this way:
“…the ability to think the kind of thoughts that have truth-values is, in the nature of the case, prior to the ability to plan a course of action. The reason is perfectly transparent: Acting on plans…requires being able to think about the world. You can’t think a plan of action unless you can think how the world would be if the actor were to succeed; and thinking the world will be such and such if all goes well is thinking the kind of thing that can be true or false…” (Fodor, LOT 2, 13)
Scientific methodology inescapably begins with propositions about what the world would be like if so and so were the case. Testing presupposes the acceptance of the truth value of a conditional statement. “If it is an acid, then the (blue) litmus paper will turn red” is a truth-value-carrying proposition the thinking about which is the necessary condition for the plan to test it. The crucial thing to notice, says Fodor, is that thinking about the truth-value of the conditional statement comes before consideration of its use. Thus, pragmatism is false.