The controversial Dutch poet and thinker, Willem Bilderdijk (1756-1831), filled his letters with observations on his own health and well-being. These frequent appraisals of his physical and mental condition served as 'meta-medical' reflections by which he enhanced his self-understanding and 'constructed' his own self. In more than 1,500 published letters that Bilderdijk wrote to different correspondents in the course of five decades, he makes it clear that he regarded his head as the main locus and source of his many afflictions. His head-related complaints enabled him to draw together medical, cultural, biographical, psychological, religious, philosophical and aesthetic strands in his life and thought. His life's motto semper idem, his indebtedness to Leibniz, his practice of spontaneously 'ejaculating' verse and his ability to contact the metaphysical world, centred on his head as both the focal point of adversity and the seat of the soul. While evidently inspired by well-known medical-cultural traditions - melancholy or hypochondria and the scholars' illness (the morbus eruditorum, on which he wrote a lengthy didactic poem) - Bilderdijk's meta-medical reflections on sickness, identity, and poetry at the same time illustrate the complexities involved in the often highly individual, early modern understandings of illness. © The Society for the Social History of Medicine 2005, all rights reserved.