This chapter examines through a disability-studies lens two texts by eighteenth-century British author Daniel Defoe, the famous shipwreck novel Robinson Crusoe (1719) and the pamphlet about Peter the Wild Boy titled Mere Nature Delineated (1726), in light of the present-day “We are all disabled” trope. Both texts warrant attention because they illuminate pitfalls in conceptualizing sameness and difference, especially in light of what is today known as developmental disability. In Crusoe, Defoe’s titular narrator implicitly takes up a universalizing view of mental disability in which it is understood as ubiquitous, a figurative category encompassing all “Mankind” due to Original Sin. Through Crusoe, Defoe seems to be saying “We are all disabled.” In Mere Nature, Defoe implicitly backs away from such a universalizing stance, acknowledging through his encounter with Peter the Wild Boy that gradations of mental deficiency exist: while all “Mankind” may be touched with mental disability, some forms of it are significant enough to require life-sustaining support. Against the backdrop of these two texts, the chapter concludes that the “We are all disabled” trope, while well intentioned, weakens the argument that some people need more care than others in order to survive.