These two aspects of highly developed science, involving progressive broadening and deepening of explanations over time, allow us to overcome the pessimistic view that current science is likely just as transient as old, superseded theories and concepts, such as phlogiston. I don't know of a single broadened and deepened scientific theory that has turned out to be false. Of course, inference to the best explanation and any other kind of evidence based thinking is fallible. There is always the possibility that new evidence will be gathered or new hypotheses will be generated showing that our current ideas are wrong. But the coherence of the atomic theory of matter and the germ theory of disease, not only with what they explain but also with underlying mechanisms that explain them, makes me confident that they will be not be superseded. Such theories not only have constructed concepts and hypotheses; they also seem to capture important aspects of reality.