Border Lines of Knowledge in Some Provinces of Medical Science is an 1862 lecture by Oliver Wendell Holmes Sr. (1809-1894), delivered as the introductory address to the medical class at Harvard University, where Holmes served as Parkman Professor of Anatomy and Physiology for thirty-five years. Holmes was a working physician and medical teacher long before his literary fame, and his 1843 paper on the contagiousness of puerperal fever was a landmark of American medical science that anticipated the germ theory. This lecture surveys the boundaries of what was then known in the medical sciences, urging students toward honest acknowledgment of ignorance as the starting point of inquiry. The piece shows the scientific side of the author best known for the Breakfast-Table essays. Free PDF download available on BDeBooks.