This essay examines Latour’s impact on writing studies through his attention to the “practice” of writing as an ontological exercise. Responding to Latour and Yaneva’s article “‘Give Me a Gun and I Will Make All Buildings Move’: An ANT’S View of Architecture,” I argue that Latour (and others), situate writing as a space for exercising the messy ontologies within which we find ourselves composed. I more fully reenact this claim through my essay by examining ontologies as written in practice, with practice, and through practices of composition(ism).