CHAPTER THIRTEEN GUNNAR KARLSSON’S ALTERNATIVE THEORY: THAT HISTORICAL PLAGUE WAS PURE EPIDEMICS OF PRIMARY PNEUMONIC PLAGUE Introduction G. Karlsson presented his alternative theory to the international com- munity of scholars in a paper published in Journal of Medieval History in 1996 where he argues that two late medieval epidemics in Iceland and more generally that plague in medieval Europe were pure epidem- ics of primary pneumonic plague.1 For his epidemiological interpreta- tion, Karlsson bases his alternative theory directly on Morris’s assertion of the occurrence of pure epidemics of primary pneumonic plague, a modality of plague disease spread by interhuman cross-infection by droplets. Th e concept of a pure epidemic of primary pneumonic plague implies that the origin of the epidemic is not a case of bubonic plague which develops secondary pneumonia but a case in which the fi rst vic- tim contracted pneumonic plague directly by inhalation of infected droplets into the lungs. Karlsson’s paper follows quite closely and draws heavily on a paper he published together with S. Kjartansson in an Icelandic journal in 1994 on two supposed plague epidemics in Iceland in 1402–4 and 1494–5 respectively.2 He is clear about its objective: “Th e present article [as the fi rst in Icelandic] can be seen as a defence of the late Jón Steff ensen against Benedictow’s critique of his conclusions,” namely, that these epidemics, and also the Black Death of 1348–9 in Norway were primary pneumonic plague.3 Th us, the central feature of Karlsson’s (and Karlsson’s and Kjartansson’s) paper on the two supposed plague epidemics in fi ft eenth-century Iceland is a comprehensive and sharp criticism of my doctoral thesis (1993, repr. 1996). Th e apparent objec- tive was to clear the way for his own theory that the epidemics were 1 Karlsson 1996: 263–84. 2 Karlsson and Kjartansson 1994: 11–74. 3 Steff ensen 1973. 40–55. O. Benedictow - 9789004193918 Downloaded from Brill.com09/29/2021 07:22:21AM via free access 494 chapter thirteen pure epidemics of primary pneumonic plague: the epithet “pure” deter- mines that they were without any basis or origin in fl ea-borne plague from rats (or other rodents) or cases of human bubonic plague.4 Th us he thinks that the contagion was the bacterium Yersinia pestis, as in the case of bubonic plague, but the process of dissemination was interhu- man cross-infection by droplets and not transmission by rat fl eas at any stage of the epidemic process. Th is immediately presents the insur- mountable problem of how primary pneumonic plague could arise in the complete absence of bubonic plague and in the complete absence of rats, a problem he surprisingly does not identify or try to explain (and the editors and consultants of the Journal of Medieval History did not fi nd signifi cant). Alternatively, he might have launched a theory of importation, which he conspicuously fails to do and, as we shall see, for the very good reason that this would disclose another insurmountable problem, which is that there is no place abroad whence plague in any form could have been imported into Iceland in these years (another problem which the editors and consultants of the Journal of Medieval History did not fi nd signifi cant). Th e Icelandic epidemics exhibit such peculiar features that Karlsson, as the fi rst of the advocates of alternative theories, has to invent some suitable mutations in order to defend his theory. He does not consider that his assertion as to the occurrence of these mutations can move from the status as arbitrary or speculative to the status as tenable (at any level of validity) only by meeting some elementary methodo- logical requirements, namely to explain to the scholarly community: (1) why and how and by which process of evolutionary selection this mutant strain or biovar came into being; (2) when and where, in Iceland or abroad, this mutant strain of primary pneumonic plague originated and developed; (3) whether this mutated variant miraculously came into being twice; and (4) where on earth (literally) it had been in the meantime (another problem which the editors and consultants of the Journal of Medieval History did not fi nd signifi cant). Undaunted by these formidable problems, Karlsson expands the per- spective of his theory from its tiny and isolated Icelandic territorial base in the middle of the North Atlantic to argue that historical 4 Karlsson 1996: 265. O. Benedictow - 9789004193918 Downloaded from Brill.com09/29/2021 07:22:21AM via free access gunnar karlsson’s alternative theory 495 plague in Europe generally was pure epidemics of primary pneumonic plague. On this basis, Karlsson concludes triumphantly that by having removed the black rat from the medieval plague he has more generally paved the way for asserting that the medieval plague epidemics in gen- eral, all over Europe, were primary pneumonic plague, presumably caused by that unknown mutated variant. Th ese assertions will be addressed in this chapter. Th e principal interrelationship between the advocates of alternative theories is the usual one in this case: that they accept his view that there were not rats in Iceland and that the fi ft eenth-century epidemics con- sequently could not have been rat-borne, which suits their alternative theories, but they fl atly reject his theory that these epidemics or the medieval plague epidemics generally were (pure) primary pneumonic plague.5 Th e gist of these counterarguments is, thus, that there never was a plague epidemic in Iceland, neither bubonic nor pneumonic, and Karlsson’s assertion that there were not rats in Iceland off ers an excel- lent explanation. Th e obvious implication is that the severe epidemics in Iceland were another epidemic disease or other diseases. To my knowledge, no other scholar has supported Karlsson’s view, at least not outside the Icelandic scholarly community where opinions apparently diff er sharply.6 One should note that there is a remarkable qualitative diff erence between the way Cohn and Scott and Duncan argue their rejections of Karlsson’s theory, and in my opinion, only Cohn makes his case on this point in a scholarly and scientifi cally tenable way.7 Karlsson and Benedictow I consider Karlsson’s reading of my thesis so bizarre and skewed that it is, in my opinion, grossly misleading and I hope I may be excused for considering it an expression of the weakness of his case.8 In my 5 Cohn 2002: 23, 51; Scott and Duncan 2004: 182. See also Twigg 1984: 68, 161–8. 6 Karlsson’s (and Kjartansson’s) paper’s were discussed at a conference in Iceland and met with much criticism; papers from this conference are published in Sagnir 1997. 7 Cohn 2002: 22–3. 8 Th is is even more the case for the original paper in Icelandic, Karlsson and Kjartansson 1994, but since very few read Icelandic or Icelandic scholarly journals, this is not important in this context, only to the Icelandic scholarly community. Also the off ensive comments on my work can, therefore, be ignored. O. Benedictow - 9789004193918 Downloaded from Brill.com09/29/2021 07:22:21AM via free access 496 chapter thirteen thesis, I presented a detailed account of the scholarly literature on pri- mary pneumonic plague, however, to no avail so far as Karlsson was concerned. Th is highlights another feature of Karlsson’s paper: although he argues very strongly for a theory to the eff ect that the Icelandic epi- demics of 1402–4 and of 1494–5 were pure primary pneumonic plague and ends up with a triumphant conclusion with a much wider territo- rial sweep, linking the nature of “medieval plague” to this disease, he has not made any attempt to acquire scholarly knowledge of primary pneumonic plague. Not a single medical study on primary pneumonic plague can be found in his footnotes. According to traditional academic principles, this ought to mean that he cannot discuss the disease that constitutes the cornerstone of his theory with the competence that only familiarity with the primary research studies and standard works on this disease can provide. Th e reason for this extraordinary approach by a scholar is presumably that the Icelandic epidemics exhibit many epi- demiological characteristics or features that are not compatible with the studies on primary pneumonic plague. Th is is where wishful thinking about mutations is introduced into his arsenal of arguments. For the same reason, he cannot avail himself of the fact that I provided a comprehensive summary of all primary studies on primary pneumonic plague and the presentation of this dis- ease in the standard works in my thesis. My endeavours to track down and present the gist of these studies does not earn me any praise, it represents, on the contrary, a signifi cant problem that has to be man- aged. Since Karlsson cannot use the corpus of scholarly works on pri- mary pneumonic plague in order to form a basis for his theory and likewise cannot use my complete presentation of it, he must fi nd a way out of this problem. His solution is to base his arguments on a second- ary paper which is profoundly fl awed, namely Morris’s sharply critical review article of Shrewsbury’s monograph where Morris was the fi rst scholar to launch a theory that the Black Death was an epidemic of primary pneumonic plague. Karlsson starts in this way: “Other diseases [than bubonic plague] are hardly considered by him [Benedictow], and all other forms of con- tagion are excluded, mainly because they are said to be insuffi cient to explain epidemics of the dimension under discussion here.”9 Firstly, 9 Karlsson 1996: 264.