If we allowed ourselves to become involved in the detail of events, it would he a long chapter indeed: fin almost twenty five years (from which saw the appearance of the Ilistoire des phlegmasies chroniques, to when their place was largely taken over by discussions on cholera), the theory of essential fevers and Broussais's critique of it occupied a considerable area in medical research, more considerable, indeed, than was warranted by a problem that could be settled so quickly at the level of'observation; but the sheer quantity of the polemics, the difficulty of reaching an understanding when one was in agreement as to the facts, the wide use of arguments that had little or nothing to do with pathology indicate an essential confrontation, the last (and the most violent, most complex) of the conflicts between two incompatible types of medical experience.