I guess this might be stunning to some people, but even as early as before 1980 there existed people who did great science, and in some cases even great philosophy, and, oh horror, they did not always knew the Bayes theorem, decision theory or too much neuroaesthetics and they were not even very rational in their private lifes. Instead, they became completely immersed in their narrow, precisely-defined field of inquiry and had the completely irrational drive that is neccessary to persist the years of labour it often takes to repeatedly subject ones beliefs to the trials of experiment and revise them times and times again. This kind of insight is not possible if you study game theory on one day, and mathematical logic on the other, and this is even without touching on the huge amount of often conflicting assumptions that underly each of those distinct fields and the ignorance of which often leads people like philosophers to nonsense conclusions.