Legacies are what we leave behind after we leave the scene, usually though not necessarily after we die. Some legacies are intangible, such as how we are remembered. Others are tangible, palpable, observable, material. Some legacies are evident while we’re still alive, for example, those of Henry Ford, Jonas Salk, and Margaret Thatcher. Others are not apparent, or at least not appreciated, until long after we’ve passed. During his lifetime the American writer and philosopher Henry David Thoreau was almost unknown, obliged to self-publish most of his essays and poems.