Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Philosophers throughout the ages have had a great deal to say about philosophical skepticism, but have generally spent very little time clarifying what exactly they mean by it. Nor have they given much attention to the basic origin and structure of this problem, of which they so frequently and glibly speak. In this thesis I argue that the problem of skepticism can be best understood as a family of reflective, deductive paradoxes centering around the apparent deductive closure of the concept of knowledge. That is, I argue that there are apparently reasonable assumptions which we make regarding the knowledge predicate, each supported by independent plausible considerations, which when taken together in their reflective, deductive consequences entail explicit contradictions. This group of reflective paradoxes, I call the family of skeptical paradoxes, or, for simplicity, the skeptical paradox. The crucial assumptions employed in the formulation of this family of paradoxes are (i) the principle of evidential underdetermination, (ii) the common-sense assumption that the knowledge predicate does have a real extension, and (iii) the principle of minimum epistemic rationality, Em. This last, Em, is an invention unique to this writing. It is a principle based on the simple idea that we can learn through reasoning, and, furthermore, specify the conditions under which such learning occurs. Although it is not closed strictly under any known form of logical implication, nevertheless, under appropriately specified conditions the knowledge operator can exhibit epistemic, and skeptically significant closure-like properties.;The first four chapters of this writing are devoted to the analysis of the problem of skepticism described above. The first two chapters are preliminary. The fifth chapter is an attempt to give some coherent direction to any further discussion as to how to solve or resolve the skeptical paradox, either positively or negatively. In it, I also entertain the suggestion that the skeptical paradox is the result of systematic semantic misconception regarding the extent and nature of the concept of knowledge.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.