At a climactic—and, indeed, incendiary—moment in Bernard Williams’ classic essay, “Internal and External Reasons,” Williams says that those who advance moral criticisms by appealing to so-called external reasons are engaging in “bluff”. Williams thus alleges that condemning certain actions of others as somehow not only immoral, but also irrational or contrary to reason is nothing more than a kind of pretense. To say that a favorite pastime that so many of us happily engage in is empty, well—to use an American colloquialism—“them’s fightin’ words!” Indeed, in criticizing certain moral criticisms in this way, Williams’ words are fightin’ words about fightin’ words. Why does Williams proffer these meta-fightin’ words? Readers—and indeed perhaps Williams himself—have struggled to articulate a precise argument for this claim that there are no external reasons and that those who try to invoke them in criticism of others are engaging in bluff. Thus, the force of Williams’ point has remained, at best, elusive, perhaps even to Williams himself. In this paper, I first want to defend Williams’ claim that the appeal to external reasons is illegitimate. But I will do so from a perspective that is radically different from the ones usually at work in considering Williams’ position. Indeed, this perspective is one that may or may not (probably not!) be in the spirit of Williams’ actual reasons for rejecting external reasons, so it is important to keep in mind (as I will remind you from time to time) that I am not offering an interpretation of Williams here. The distinctive aspect of my approach is that I argue that a rationalist line of thought can support Williams’ claims. To bring out this line of thought, I will examine the metaphysical commitments of those who engage in what Williams calls bluff. I will then reject those commitments on powerful and widely popular rationalist grounds. I will, in other words, endeavor to support Williams’ charge of bluff by investigating what I call the metaphysics of bluff and by offering a rationalist critique of that metaphysics. Michael Della Rocca is Andrew Downey Orrick Professor of Philosophy at Yale University. He has published widely in early modern philosophy and in contemporary metaphysics. His most recent book, The Parmenidean Ascent (Oxford 2020), defends a radical form of monism in metaphysics, philosophy of action, epistemology, and philosophy of language. This podcast is an audio recording of Dr Della Rocca's talk - "Moral Criticism and the Metaphyscis of Bluff" - at the Aristotelian Society on 6th June 2022. This recording was produced by the Backdoor Broadcasting Company.