This dissertation examines the connection between Craig's theorem and scientific instrumentalism. The main question to be answered is whether the former can be used to support the latter. A negative answer to this question is defended in the dissertation. ;The first two chapters present a detailed expository account of the proof of Craig's theorem and also of the process by which theoretical terms are to be eliminated from scientific theories according to the method developed by Craig. Emphasis is placed on (...) those points which are relevant to later discussions. ;There have been several arguments against using the Craigian method of eliminating theoretical terms and against replacing a scientific theory by its Craigian revised theory . The third chapter is devoted to two of those arguments. The first is meant to show that the distinction between observational and theoretical terms is untenable and hence that the Craigian method cannot be used to eliminate theoretical terms. The second is intended to show that a Craigian revised theory does not always preserve the whole inductive power of its original theory and hence that it cannot replace the original theory. Both arguments are analyzed in detail and rejected. ;The fourth chapter argues that Craig's theorem cannot be used to support scientific instrumentalism: it is argued that a Craigian revised theory may lack the explanatory power of its original theory. In the course of arguing the above point, ten outstanding theories of explanation are considered. It is argued that no matter which account of explanation is adopted, a Craigian revised theory cannot always preserve the whole explanatory power of its original theory. ;In the fifth chapter, the "theoretician's dilemma" of Carl G. Hempel's is examined. It is argued that, in virtue of the explanatory shortcoming of the Craigian method, the theoretician's dilemma cannot be used to support scientific instrumentalism. (shrink)