Understanding changing perceptions of “great works”— what books are included in a canon at a given moment in history, why certain works make the cut while others fall to the wayside, and tracking down the individuals responsible for these decisions—is a hobby of mine. I have written about it many times on the Scholar’s Stage. This week I came across an interesting example of cannon formation in action. William Osler was one of the founding physicians of John Hopkins Medicine, creator of the hospital residency system, inventor of much of the hands-on medical pedagogy still used in medical schools today, and one of the most famous doctors of his day. On the final page of Aequanimitas, a collection of Osler’s lectures and orations published in 1904, is a list of books that Osler believes should be on every medical student’s bookshelf. He suggests that while in medical school young doctors-to-be should spend the last 30 minutes of their night reading from this chosen library.