Charles Brockden Brown’s Edgar Huntly (1799) narrates two scenes of panther attacks. In the first scene, Huntly’s mind is paralyzed, while in the second, Huntly’s body kills a stalking panther by hurling a tomahawk across a dark cave, an effort stemming from our bodily “constitution.” This introduction argues that this artist not only troubled the mind-centered ontology of consciousness—the Cartesian idea of the mind’s dominance over the body—but also explored the ontological alternatives that centered the expressions of our material body’s “constitution.” It both uncovers the posthumanist accents of this work, and reveals the way it prods us to refurbish posthumanism by historicizing it. Starting with Brown, this introduction thus recovers a set of texts focused on “minding the body,” on not simply eroding the philosophical distinction between the mind and body in order to trouble a mind-centered ontology and imagine a body-centered alternative to it, as posthumanism does. It also reveals the way artists used the expressive agency of these historical bodies to imagine less repressive alternatives to nineteenth-century structures of power—including chattel slavery, market capitalism, and patriarchy—whose claims to dominance involved reducing the body to little more than mindless matter.