For obvious reasons a number of historians have looked back to Europe in the 1920s to see what lessons can be learned from the rise of fascism during that time. Some, such as Timothy Snyder, have drawn powerful lines of connection to the period, while others, like Enzo Traverso, have cautioned that the two situations are too dissimilar to be productively compared. At issue, fundamentally, is the old principle of historia magistra vitae (history as the teacher of life), which assumes, as Reinhart Koselleck has demonstrated, a basic constancy in human experience over time and across culture—an assumption that is dubious for many of us, to say the least. Already before the rise of fascism one hundred years ago there were intimations of “the fascist personality,” and even though characterological types are subject to the same objections as historical lessons (how can any such transcendental category be valid?), some of these speculations might still be instructive, if for no other reason than they can point to differences in the present. As Koselleck suggests, the recognition of incomparability is a historical lesson in its own right.