Abstract

This paper investigates the justification of certain beliefs central to scientific realism. Some have claimed that the underdetermination of a theory by empirical evidence implies that belief in the truth of the theory and in the existence of the corresponding unobservable entities is unjustified. It is argued that the justification of certain realist beliefs is similar to the justification of our perceptual beliefs. Neither are justified by argument from more basic beliefs, and their underdetermination by the evidence does not affect their justification.