"Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality" by Manjit Kumar (2008)

Heisenberg, Schrödinger, Bohr, and Einstein each, with near-religious conviction, believed in his own version of reality, despite no experimental evidence could discriminate among them. The physicists' debate was not futile, however. Even though the application of existing knowledge is unaffected by the fiction behind equations, the advancement of future science is. Speculations about the unobserved reality help generate new hypotheses and prioritise pending experiments. Furthermore, even if, say, Heisenberg were unsure about the verity of his vision (which he, a scientist, must have been), the society would nonetheless want him to passionately advocate that vision, thereby encouraging others to harness their arguments.