I try to reconstruct the hidden agenda of nineteenth-century British controversy between Utilitarianism and Intuitionism, going beyond the image, successfully created by the two Mills, of a battle between Prejudice and Reason. When examined in depth, competing philosophical outlooks turn out to be more research programs than self-contained doctrinal bodies, and such programs appear to be implemented, and indeed radically transformed while in progress thanks to their enemies no less than to their supporters. Controversies, the propelling devices of research programs, (...) are real-words affairs, and philosophers do not engage in them just for the sake of the argument, but in order to win, and alignments are defined on the basis of strategic and tactical requirements that cross the boundaries of disciplines. I suggest that good objections and counter-objections, and most of all amendments of doctrines, were incidentally produced in the course of the fight, and they were no less valuable because of their being more side-effects than sought-for discoveries. (shrink)