An editor immediately runs a substantial risk when titling a book "Essential Papers on…," since readers will expect to see their favorite classics. As I began perusing Essential Papers on Post Traumatic Stress Disorder, I had in mind, of course, my own list of essential and classic papers that I hoped to see in the volume. The problem is that lists of essential papers often only overlap in some areas. This is true here. One would expect to see Lindemann’s paper on symptoms of acute grief, Pynoos and Eth’s paper on children witnessing violence, Shore’s study of Mount St. Helens, and at least one paper by Bonnie Green and Jack Lindy. These are present. Similarly, Lifton and Olson’s paper on the Buffalo Creek disaster, published in 1976, was a major contribution to our recognition of the impact on health and community function of the threat to one’s life and exposure to death. Eitinger’s work on concentration camp victims represents an entire genre of publications on which the studies of posttraumatic stress disorder (PTSD) have been built. However, it is surprising to find a paper on eye movement desensitization in such a volume. What makes a paper essential, what makes it a classic, is much in the eye of the beholder.