...it would not be quite right to say that the problem is unsolvable in principle; only so complicated that it is not worth anybody’s time to think about it. So what do we do?In probability theory there is a very clever trick for handling a problem that becomes too difficult. We just solve it anyway by:(1)  making it still harder;(2)  redefining what we mean by ‘solving’ it, so that it becomes something we can do;(3)  inventing a dignified and technical-sounding word to describe this procedure, which has the psychological effect of concealing the real nature of what we have done, and making it appear respectable.