I will try to analyze Harry Crane's article "Naïve probabilism" and formalise what is, for me, "the problem of medicine" (being blind to scale and his consequences). I will introduce Post-Normal Science, criticise the Geoffrey Rose's approach, praise Marc Jamoulle's work and concluding that not all the precautions (at different scales) are the same "ting". A short list at the end is exposed in a summary style. This is for starting a debate about epistemology of medicine and his (for me) lack of skin in the game and second-order thinking. Not a closure. Massive review is welcome (and necessary).