Vindication : A Reply to Paul Teller

1. One of the few things about which I am optimistic is that we are close to a clear understanding of scientific inference. I think that, as a result of the work of many contributors, all the elements for a complete theory of scientific inference are at hand — although it is risky to say so, especially in view of the dramatic history of deductive logic after it was commonly supposed to have been a complete science. However, even if the requisite elements have all been discovered, there is still hard work to do in properly combining them, for what is needed is not eclecticism but a piece of intellectual architecture. Professor Paul Teller has criticized the architectural design that I proposed in my essay "Scientific Inference." I tried there to justify scientific inference in two stages. The first stage was a priori, utilizing a kind of vindicatory argument. The second stage was a posteriori and relied upon certain factual propositions about the world, which themselves have been incorporated into our scientific world view as a result of scientific inference. Teller claims that nothing was accomplished in the first stage, and he suggests that the only justification which is possible or needed for scientific inference will be a posteriori. Teller's criticisms of my a priori arguments are forceful and point to weaknesses in my design. It probably was a mistake to make a sharp separation between the a priori and the a posteriori stages in the justification. I do not concede, however, that we must dispense with vindicatory arguments. Indeed, I feel sure that when he works out the details of his a posteriori justification of scientific inference, he will inevitably find that he also must resort to them. The following examination of his criticisms leads