Dugald Owen

The basic methods that have been used for describing bound-state quantum electrodynamics are described and critically discussed. These include the external field approximation, the quasi-potential approaches, the effective potential approach, the Bethe–Salpeter method, and the three-dimensional equations of Lepage and other workers. Other methods less frequently used but of some intrinsic interest such as applications of the Duffin–Kemmer equation are also described. A comparison of the strengths and shortcomings of these various approaches is included

I develop a theory of meaning in the form of constraints on the interpretation of a speaker's utterances as an approach to issues in the philosophy of language and mind. The constraints fix the logical form assigned to the speaker's sentences and guarantee that the interpretations reveal the speaker to be a rational agent. Satisfaction of the demand that semantic assignments capture cognitive significance requires modification of the truth-conditional scheme of generating interpretations as theorems of a truth theory , for such a scheme cannot accommodate indexical expressions. I propose that semantic assignments take the form of statements by the theorist of the meanings of given utterances, and show how this allows content clauses to reflect cognitive significance. Satisfaction of the demand that the account yield interpretations for all potential utterances of a speaker requires solution to a recalcitrant problem in semantic theory: how to generate interpretations capturing cognitive significance for utterances containing multiple embeddings of expressions introducing intensional contexts, e.g., "says that", "believes that", etc. I show how this may be accomplished in a theory taking the form I propose. ;I formulate semantic assignments to predicates, names, and indexical expressions in accord with my constraints. Two versions of the Fregean demand that meaning capture cognitive significance are explored. I argue that the stronger demand that meaning explain and not merely reflect cognitive significance cannot be met. I defend the thesis of indeterminacy of interpretation, but oppose what Davidson sees as one of its principal sources. ;The account of meaning and thought content I develop may be considered "externalist", since states of the world external to an agent's mind are essential to the interpretation of her words and the content of her thoughts. An alternative "internalist" position holds that an agent's meanings and thoughts are conceptually independent of the world outside her head. I evaluate the internalist conception of mind and argue that it fails to meet the standard of correct attribution set by ordinary, informed judgements of meaning and thought. I conclude in favor of the externalist conception

Students often invoke quantum mechanics in class or papers to make philosophical points. This tendency has been encouraged by pop culture influences like the film What the Bleep do We Know? There is little merit to most of these putative implications. However, it is difficult for philosophy teachers unfamiliar with quantum mechanics to handle these supposed implications in a clear and careful way. This paper is a philosophy of science version of MythBusters. We offer a brief primer on the nature of quantum mechanics, enumerate nine of the most common implications associated with quantum mechanics, and finally clarify each implication with the facts. Our goal is to explain what quantum mechanics doesn’t show.