This chapter is about the view that we are material things constituted by organisms; this view is advocated by Baker, Shoemaker, and others. Each of us is made of the same matter as an organism, but our persistence conditions or essential properties preclude our being organisms ourselves. This goes together with the general view that qualitatively different objects can be made of the same matter at once: constitutionalism. Constitutionalism is supported by arguments involving the persistence of artifacts. It is argued, however, that the view faces the thinking-animal problem, that it rules out any principled account of when one thing constitutes another, that it cannot explain why our boundaries lie where they do, and that it conflicts with a popular claim about synchronic identity.
Keywords: animal, artifact, Baker, boundaries, constitution, Shoemaker, synchronic identity