I love watching videos from Richard Feynman on Youtube. Apart from being entertaining, Feynman in the video below does explain quite subtly about what constitutes a good scientific theory, and what doesn't. He is right about the fact that good theories are precise theories.
The video also makes me jealous of natural scientists. In the social sciences, almost all processes and causal relationships are contextual, as opposed to the natural sciences. For example: in survey methods, nonresponse is one of the phenomena that is contextual. Nonresponse always occurs, but the predictors of nonresponse differ across countries, survey topics, time, survey mode, and subpopulations. In other words, that is what makes building a theory about nonresponse so difficult.