 Einstein was self-consciously opportunistic in his methodological eclecticism, but philosophers wanted to find a more general rationale for freeing scientific theorizing from operationalist micro-management. The crux of the problem here for the operationalist is that theoretical concepts are much too useful in science. Bridgman actually acknowledged from early on that there were good theoretical concepts that were not amenable to direct operationalization, illustrating the point with the example of stress and strain inside a solid body (1927, 53–54), and the wavefunction in quantum mechanics (Bridgman in Frank 1956, 79). Bridgman saw clearly that these theoretical concepts only had indirect connections with physical operations, but he did not see any problems with that. He in fact went so far as to say: “there need be no qualms that the operational point of view will ever place the slightest restriction on the freedom of the theoretical physicist to explore the consequences of any free mental construction” (Bridgman in Frank 1956, 79; see also Bridgman 1949b, 256). All that was required was that the theoretical system touched the operational ground somewhere, eventually. However, in that case Bridgman’s message was the same as Einstein’s, as the physicist R. B. Lindsay pointed out (Lindsay in Frank 1956, 71–72).