Probability, propensity and probabilities of propensities (and of   probabilities)
  The process of doing Science in condition of uncertainty is illustrated with a toy experiment in which the inferential and the forecasting aspects are both present. The fundamental aspects of probabilistic reasoning, also relevant in real life applications, arise quite naturally and the resulting discussion among non-ideologized, free-minded people offers an opportunity for clarifications. 
Giulio D'Agostini
math.HO math.PR physics.data-an physics.hist-ph stat.OT