 Philosophy of science, throughout the early- and mid-twentieth century, was predominated by attention to examples, problems, and concepts from physics. Not surprisingly, the philosophical insights produced a vision of how science worked that was modeled on physics. Scientific explanations, as one example, arose from the derivation of phenomena from physical laws of nature; rainbows are explained by reference to the laws of reflection and refraction, alongside the position of the sun, the position of raindrops, and the position of the person seeing the rainbow. Scientific progress, as another example, proceeded by way of higher-level sciences reducing to lower-level sciences; thermodynamics (with its concepts of temperature and pressure), the thought went, was reduced to statistical mechanics (with its concepts of mean kinetic energy and force) (entries:  scientific reduction;  intertheory relations in physics;  scientific progress;  laws of nature). 