The title of Steven’s dissertations is “Accepting Defeat: A Solution to Semantic Paradox with Defeasible Principles for Truth”. Stewart Shapiro was the advisor and chair of the dissertation committee. Neil Tennant and Chris Pincock were committee members.  Here’s the dissertation abstract:

The central aim of this thesis is to argue that the solution to semantic paradox consists in viewing principles for semantic notions as defeasible. In service of this aim, I argue first that the main problems posed by semantic paradox are for the foundations of linguistic semantics. I then argue that these problems require us to view certain principles as defeasible, which means that we are warranted to use those principles unless we have evidence to the contrary. The most plausible such principles to view as defeasible are those for semantic notions, like the T-rules for truth, according to which from `P' one can infer ``P' is true' and from ``P' is true' one can infer `P'. Moreover, viewing the principles as such is sufficiently rigorous for the science in which they are to be used and provides the best description of our ordinary use of them. The explanation for why the principles are defeasible is provided by viewing the notions as open-textured, which means that however tightly we define these notions there will remain certain cases unsettled by those definitions. I complete the investigation by modelling defeasible reasoning with the principles in a default logic and study the theories that result.