We tend to assume that, at least in principle, there is nothing we may not know. The idea that being born, say, in the second half of the twentieth century in the US of A might limit or shape what we may know seems odd to us, insulting almost. And yet periods of history are defined by styles of thinking, root ideas and thought-formations that allow some ideas, but not others, to be thought. Such periods in history are called epistemes by the French philosopher Michel Foucault, who points, for example, that a capacity to locate the common roots of French, Spanish and Italian languages in Latin requires an idea no intelligent person could entertain in the Classical episteme of the 1750s, even a person as intelligent as, say, Voltaire. The idea that a language might shift and develop—evolve, we would say—only arrives in the 1800s with Darwin and what Foucault called the Historical episteme. All of this, of course, begs the question: as citizens of the West in the second decade of the twenty-first century, what is it today we cannot think? “Tell me what that is, Foucault,” I want to say, “then watch me go right there and think it.” Well, why not, in fact, get started right away, now, together, feeling our way toward it—the un-thought.