Abstract

There has been much discussion arising from Reichenbach's distinction in the philosophy of science between the context of discovery and the context of justification. More recently, some have also begun to distinguish between these and the "context of pursuit" at which point scientists are pursuing a theory or hypothesis that has been suggested as plausible, but is not yet deemed acceptable. However, there has been relatively little work done on characterizing this process by using specific scientific examples. In this talk, I consider Millikan's 1916 experiment on the photoelectric effect, and its relation to Einstein's light quanta hypothesis in order to clarify the role of hypotheses in the context of theory pursuit. I argue that Millikan's results did not directly support the light quanta hypothesis, but that they did constrain the possible theories that could be subsequently developed. Thus, a hypothesis can be useful for guiding research, but we must be careful to evaluate whether the experimental results genuinely support the hypothesis or not.