Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Matthias P. Steup

Committee Chair

Matthias P. Steup

Committee Member 1

Michael A. Bergmann

Committee Member 2

Rod J. Bertolet

Committee Member 3

Paul Draper

Committee Member 4

Baron Reed


In recent years, questions regarding the truth conditions of knowledge ascriptions (sentences of the form ‘S knows that P’ where S is a subject and P a proposition) and knowledge denials (sentences of the form ‘S doesn’t know that P’) have been at the fore of a certain sector of analytic epistemology and philosophy of language. These questions include “How do we determine the truth conditions of a particular knowledge ascription or denial?”, “What sorts of factors are relevant in this determination?”, and “Is context among the relevant factors in a non-trivial way, and if so, how?” A variety of proposals have been generated in order to answer these questions—including proposals that offer a primarily semantic response. However, very little attention has been given to the possibility that part of the best answer to these questions about the truth conditions for knowledge ascriptions and denials is to posit that ‘knowledge’, ‘knows’, and their cognate terms are ambiguous.

This dissertation offers a defense of a proposal along these lines. More specifically this dissertation is a defense of the ambiguity theory of ‘knows’. The ambiguity theory of ‘knows’ is the view ‘knows’ and its cognates have more than one propositional sense (i.e. a sense that can properly be used in ‘knows that’ constructions) and that which sense of ‘knows’ is being employed in a knowledge ascription or denial plays a role in fixing the truth conditions of a knowledge ascription (in virtue of contributing to the meaning of the claim). In this dissertation, this claim is defended first by making clear how the ambiguity theory differs from others proposals on offer, second, by comparing the ambiguity theory to other leading proposals and arguing that the ambiguity theory fares as well if not better, and third, by providing other independent arguments in favor of the view. My hope is that the work done here will give the ambiguity theory a more prominent presence in the relevant philosophical debates.

Included in

Epistemology Commons