The growth of theories

A very naïve view of science might go something like this: Scientists encounter a range of observable phenomena for which they have no explanatory account. Hypotheses are generated from the imaginations of the scientists who seek to explain the phenomena in question. These hypotheses are tested against the experimental results. If they fail to successfully account for those results, the hypotheses are rejected as unsatisfactory. But if they succeed in predicting and explaining that which is observed, they are accepted into the corpus of scientific belief. Then scientific attention is turned to some new domain of, as yet, unexplained phenomena.

This simple-minded picture of science has been challenged for a variety of reasons. Some are skeptical regarding the possibility of characterizing theory-independent realms of observational data against which hypotheses are to be tested. Others have noted the way in which the testing of hypothesis by data is a subtle matter indeed. It has often been noted, for example, that even our best, most widely accepted fundamental theories often survive despite the existence of “anomalies,” observational results that are seemingly incompatible with the predictions of the theories.