Given that Caleb Carr’s latest novel, The Legend of Broken, was released in paperback last month, I’ve decided to spend this week overviewing how philosophers and physicians of the Dark Ages (the time period in which the novel was set, typically considered to span the fourth or fifth century A.D. to the eleventh century A.D.) believed the human mind and brain functioned. To quickly recap what was covered during Part One earlier this week, throughout this period it was generally believed that cognitive processes such as mental imagery and memory (known as particular knowledge) took place in a three-part ventricular system located in the brain. As this theory of the inner senses was the most widely cited theory of human cognition between approximately the fourth and sixteenth centuries A.D., we are returning to the theory today to discuss how it allowed medieval physicians to account for phenomena such as dreaming, and to eventually provide an explanation for certain types of mental illness as well.
However, before diving straight back into the theory of the inner senses, we first need to overview Hippocrates’ humors theory, which was perhaps the most influential theory of medicine prior to the modern age, with aspects still widely believed well into the eighteenth century. Between approximately the twelfth and sixteenth centuries A.D., the theory of the inner senses was typically combined with the humors theory by scholars such as Avicenna who took the strengths and weaknesses of both into consideration in order to produce a unified theory of human cognition that would explain individual differences in cognitive functioning (e.g., memory ability), personality differences, and mental illness. Prior to this point, however, the two theories appear to have remained fairly separate, so in order to understand how mental illness was perceived and treated during the earlier time period under consideration here, we need to overview the theories separately. | Continue reading →