Tears in Ancient and Early Modern Physiology: Petrus Petitus and Niels Stensen

Abstract

In 1661 the French physician, philosopher and poet Petrus Petitus published a Neo-Latin treatise, De Lacrymis. In book 1 he treated systematically according to Aristotelian rules the causa materialis of tears; in book 2 the causae efficientes (tristitia-gaudium) and causa finalis, whereas book 3 deals with separate problemata. His work is a cornucopia of erudition, collected from Greek and Latin sources, Hippocrates and Galen included. It may serve very well to reconstruct an ancient theory of tears and weeping. In the same period, however, Thomas Warton and Nicolaus Steno discovered the system of glands that explained the physiology of weeping. Two explanatory models, one by analogy, the other based on anatomical observation and experiment, stood side by side. After some introductory remarks on early, pre-scientific ideas on human physiology testimonia on tears and weeping in ancient literature are presented, using Petitus as ‘Fundgrube’. This section is concluded by an overview of the most common ‘physiological’ theories of tears and weeping in ancient medicine, based on analogy. After discussing ancient anatomical knowledge of the eye, we try to put the discovery of the functioning of the lachrymal glands in the seventeenth century in context. Our aim is to highlight Petitus’ On Tears as a culminating point of ancient analogical thinking, alongside the emerging science of anatomy, based on observation and experiment.