The American physicist Richard Feynman is often quoted as saying: “You can recognize truth by its beauty and simplicity.” The phrase appears in the work of the American science writer K C Cole—in her Sympathetic Vibrations: Reflections on Physics as a Way of Life (1985)—although I could not find other records of Feynman writing or saying it. We do know, however, that Feynman had great respect for the English physicist Paul Dirac, who believed that theories in physics should be both simple and beautiful.
Feynman was unquestionably one of the outstanding physicists of the 20th century. To his contributions to the Manhattan Project and the solution of the mystery surrounding the explosion of the Space Shuttle Challenger in 1986, add a Nobel Prize in 1965 shared with Julian Schwinger and Shin’ichirō Tomonaga “for their fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles.” And he played the bongos too!
In the area of philosophy of science, though, like many physicists of his and the subsequent generation (and unlike those belonging to the previous one, including Albert Einstein and Niels Bohr), Feynman didn’t really shine—to put it mildly. He might have said that philosophy of science is as helpful to science as ornithology is to birds (a lot of quotations attributed to him are next to impossible to source). This has prompted countless responses from philosophers of science, including that birds are too stupid to do ornithology, or that without ornithology many birds species would be extinct.