We discuss the unity of physics with a kind of nostalgia, for our field today is so patently diverse. We hear this diversity in the cacophony of our meeting halls, in the differing languages of theorists and experimenters, of rheologists and astrophysicists. The sheer numbers of physicists and of the papers we publish—one every few minutes—overwhelm us. Diversity has even been institutionalized: Our American Physical Society is now organized into a dozen disparate divisions, and physicists have organized many physics societies outside APS. One would expect one of the clearest expressions of the unity of physics to lie in the teaching of physics, but even that enterprise has its separate American Association of Physics Teachers. And didn't we establish the American Institute of Physics, of which APS is but one of ten members, because of the need for unity in physics?
Our will to believe, in spite of strong arguments to the contrary, that our diverse activities are part of one noble effort lends historical meaning to our work and perhaps even helps to create unity.