The Epistemic Status of Auxiliary Hypotheses: A Reply to Douven

I have previously argued that anti-realism cannot use the claim that theories have empirically equivalent rivals (EE) to establish that theories are underdetermined by evidence (UD). Douven objects that the auxiliary hypotheses needed to generate observational equivalence need not as I claimed be themselves underdetermined if (EE) is true, because they may be either compatible with observation or acceptable in the constructive-empiricist sense. I reply that these conditions are not strong enough to establish (EE): the auxiliaries have to be epistemically warranted if they are to fix a theory's observational commitments unambiguously. The support they require need not presuppose their respective observational consequences, because there are more holistic sources of warrant.     

Douven On Putnam's Model-Theoretic Argument

The model-theoretic argument, which Putnam employs to argue againstmetaphysical realism, has faced serious objections of many realist opponents.Igor Douven in his recent paper offers a new interpretation of the model-theoreticargument, which avoids the previous objections. The purpose of this paper is toshow that Douven's reconstruction of Putnam's argument is not successful, andhence that the realist objections still stand.     

A reply to Robinson

Robinson’s criticisms appear to be based on misunderstandings of the methods and logic of my paper and those of other workers. They have been clarified point by point. It is concluded that there is still no direct evidence for the lateral inhibition hypothesis as an explanation of visual interactions.     

A reply to Walsh

Walsh (1971) has added a useful analysis of the possible shape that hypothetical interacting functions must have to account for the combined effects of forward and backward masking described in my paper (Uttal, 1969). In setting the stage for his comments, however, he fails to consider other statements made in that paper.