In addition to the neglect of philosophy by medicine, emphasized in a recent editorial in this journal, there has been an equally important neglect of medicine by philosophy. Philosophy stands to gain from medicine in three respects: in materials, the conceptual difficulties arising in the practice of medicine being key data for philosophical enquiry; in methods, these data, through their problematic character, being ideally suited to the technique of linguistic analysis; and in results, the practical requirements of medicine placing a direct demand for progress on philosophical theory. The future of the relationship between philosophy and medicine depends on the development of a positive two-way trade between them.