This section dealing with black-related disease susceptibilities is the core of the book. One argument that permeates its six chapters should be a familiar one by now, namely that black disease susceptibilities, like immunities, did much to inculcate in physicians, slaveholders, and some unmeasurable portion of the literate public the idea that, from a scientific standpoint, blacks were indeed a different breed of man. At this point, however, a few words about the evidence that supports this argument seem appropriate.

Unquestionably, a good deal of the medical literature concerned with the health differences of black and white was produced in the sectional heat that led to the Civil War-produced, in the words of Todd Savitt, by physicians who … “were writing for an audience who wished to hear that blacks were distinct from whites. This was, after all, a part of the proslavery argument” and incidentally a part we treat in Section IV.

Yet, just because some physicians who wrote about black health differences were committed to the southern cause, it does not necessarily follow that they themselves were not convinced of that distinctiveness, nor that they failed to convince others. Moreover, there was also much antebellum medical literature on the black written long before the Civil War that contains no trace of political taint. Finally in this connection, notions of black-white medical differences hardly originated in North America. Rather, as we have already seen, physicians in Africa and the West Indies were aware of and writing about racial dissimilarities in disease susceptibilities long before white Southerners, physicians included, felt compelled to wield a pen in slavery's defense.