textbook quantum mechanics) but represent precise mathematical and physical challenges which call for a physical solution. As J.S. Bell appropriately stated¹ "the way ahead is unromantic in that it requires mathematical work by theoretical physicists, rather than interpretations by philosophers". It is also encouraging, for those who share this position, to see that now there are explicit proposals indicating possible ways out in which the process of measurement (and more generally all those measurement-like processes² "we are obliged to admit ... are going on more or less all the time, more or less everywhere") is analysed not in terms of vague assertions or resorting to ill-defined and/or contradictory dualistic evolution processes (the linear and deterministic evolution for microsystems and the nonlinear and stochastic wave packet reduction for the macroscopic ones) but in terms of more fundamental physical concepts. In particular, approaches of this kind, which S. Goldstein³ has appropriately denoted as "observer-free formulations of quantum mechanics", can be grouped in three categories: the pilot-wave theories: the decoherent histories and the spontaneous localization models." /> The dynamical reduction program - Ghirardi Giancarlo | sdvig press