The Purpose of a Diagnosis
In order to discover Arnau's purpose, it is useful to compare this text with others, both by Arnau and by other authors. Of course, the relationship between melancholy and magical arts is not new.
One of precedents is a passage from De universo by William of Auvergne (1231-1236). Therein William resorts to melancholy to attack the practice of divination through Apollo's mirror?[782] The medical source for his ideas on melancholic disease, considered “insanity and alienation of the right intelligence and the discernment of the reason”, is also Constantine's De melancholia, again under Galen's name. But, unlike Arnau's epistle, William attributes such magical operations not only to a deception caused by demons but also to demonic possession, in accordance with the widespread opinion that the devil uses melancholy to influence humans.[783]Therefore, we can see William as a transitional stage in the evolution from the religious view that considers a necromantic operation to be based on demonic possession towards the naturalistic conception that regards the belief in necromancy as a possible consequence of melancholy. In contrast, the naturalization process appears to have already been completed in Arnau's epistle: he does not see necromancy as an example of demonic possession but merely as a deception by the devil. And to understand how a person, especially if educated, can believe in an idea as absurd as the rationality of necromancy it is necessary to impute it to some pathological condition.
Such attribution of melancholy to the defenders of ideas that were seen as intellectual errors is also found in other contemporary authors. In his Lilium medicine (1305), Bernard of Gordon, a professor at the University of Montpellier at least from 1283, when discussing the danger of melancholy becoming a mania, says that the hidden signs of a future mania are: thinking what should not be thought, considering good or honest what is not, setting oneself unreasonable or impossible goals, about which they have a wrong judgement.
Another sign is seeing demons, black monks, dead people or other fantasies in dreams.[784] [785]Bernard's consideration of illegitimate or irrational beliefs and visions of demons as being hidden signs of melancholy recalls Arnau's diagnosis for necromancers. The difference is that Bernard indicates such hidden signs in addition to the general perceptible symptoms of melancholy, while Arnau says they are the only ones. Therefore, Bernard is more faithful to Constantine and the other medical authorities than Arnau. Indeed, there is no doubt that Constantine is one of Bernard's main sources^2 but he does not mention him like Arnau. He only cites Avicenna and Galen.
In another passage of the Lilium, Bernard also attributes melancholy to some professors and prophets:
Some consider themselves masters in all the sensible world and they begin to give lessons and teach, albeit not explaining anything rational, whereas others believe that they are prophets and that they are inspired by the Holy Spirit and begin to predict many future events regarding the world or the Antichrist.[786]
According to Michael McVaugh, the blame for both should be attributed to Arnau, his fellow at the Faculty of Montpellier, the first due to his interest in natural philosophy and the second, to his religious concerns[787] It is well known that Arnau devoted the last twenty years of his life to announcing the coming of the Antichrist and asking for Christianity to reform and fight against it. In this latter imputation, another aspect should be considered: prophesying has been seen as a possible effect of melancholic disease since Antiquity[788] Therefore, the diagnosis of melancholy was used by some late medieval authors in order to discredit opposing, and often unorthodox, opinions: Arnau blames necromancers in De reprobacione, and in turn is disgraced by Bernard on the same basis. In my opinion, this can be interpreted as a medicalization of the practice of relegating to marginality behaviors and opinions that deviated from the mainstream ideology and assimilating them into madness[789]
Many years later, in his religious controversies with scholastic theologians, Arnau also imputed ideas he considered wrong to mental disorders.
In his attack on Martin de Ateca (1304), he states that his adversary’s unfair arguments could only be excused by insanity (vesania or lethargy), although he is somehow responsible due to having an unhealthy lifestyle.[790] In the debate with the Dominicans of Girona (1302 or 1303), he describes those who misunderstand him or the Holy Scriptures as insane or heretic[791] [792] In my opinion, such attributions of mental illnesses are not merely metaphors, as Joseph Ziegler suggests,39 but a possible explanation for the irrationality of the ideas held by his detractors according to the learned medical tradition.These other examples help to understand Arnau’s purposes for diagnosing necromancers with melancholy. To discredit the views of his dialectic opponents (both defenders of necromancy or opponents of his religious thought), Arnau cannot diagnose damage to the rational faculty if he does not show that this is the only visible symptom of their disease, because in his eyes they had no health problem other than a misguided belief.
Beyond its undeniable polemic value, the idea that holding opinions contrary to reason may be an indication of a lesion of the rational faculty is well- rooted in Greek-Arabic Galenism, as we have seen. In different contexts, with different purposes and concretions, Arnau’s, William’s and Bernard’s statements are the result of ideas, born in ancient medicine and developed by medieval Galenism, regarding the harm caused by melancholy to cognitive faculties, both the imaginative and the rational, which would be the origin of the behavioral disorders observed in the mentally ill. In fact, considering someone’s irrational thought to be an effect of a physical disease is an extreme consequence of the somatic vision held by Galenism of mental illness from Galen himself.[793] In De reprobacione, this use appears for the first time in Arnau's work and might be favored by melancholy's relationship with magic and the devil observed in preceding authors, such as William of Auvergne.
But the closest seems to be Thomas Aquinas, when he imputes a “bad disposition of intellect” to necromancers, in addition to their poor moral disposition, because of the irrationality of their beliefs and practices[794]It is also revealing that Arnau considers the rational faculty (estimatio) to be injured, but not the imaginative, when according to medical tradition both of them could be affected by melancholy. This is the basic difference between his view and the imputation of melancholy often applied to witches, especially during the fifteenth and seventeenth centuries, by some physicians and writers, such as Johann Weyer or Reginald Scott, who tried to extenuate their guilt. In that case, witches' delusions were often attributed to an injury to the imagination produced by melancholy. Therefore, acts of witchcraft should not be considered real but hallucinations induced by the disease[795] In contrast, when Arnau says that it is the rational faculty that is injured, he is silent about the possibility of necromancy having real effects, but merely denies the interpretation given by its practitioners. The purpose of the epilogue is to discredit necromancers’ beliefs, not the attenuation of their moral responsibility, even though Arnau actually diverts their wrong opinions from moral corruption to the physiological.[796] We must bear in mind that earlier in the same epistle he accused necromancers of being “the worst sinners” (ll. 179-180).