The trouble with case-studies, and the active philosophical function of history

What can we conclude from a mere handful of case-studies?  This has been a vexing question for integrated history and philosophy of science (HPS).  The field of HPS has witnessed too many hasty philosophical generalizations based on a small number of conveniently chosen case-studies.  This was seen as detrimental to philosophy and history both.  On the philosophical side, case-studies may end up as empty gestures parading as evidence confirming one’s pre-existing biases about the nature of science and its methods.  At best what we get is “grand conclusions by induction from absurdly small samples”, in Richard Burian’s words (2001, 388).  The deeper problem, as Joseph Pitt (2001, 374) put it, is that “if philosophers wish to use historical cases to bolster their positions, then . . . we will have to figure out how to relate the history to the philosophical point without begging the question.”  On the historical side, even philosophically sympathetic historians despaired of the oversimplifications that philosophers were apt to make of complex historical material through the case-study approach.  John Hedley Brooke’s complaint is typical and apt (1981, 257): “When the circumstances and the problems were so complex, the isolation of a single philosophical or methodological point as the key to an adequate explanation must lead to a distortion of emphasis.”  I believe that the neglect to clarify the nature of the history–philosophy relationship in case-studies has contributed decisively to a widespread disillusionment with the whole HPS enterprise.