Organisms receded from view in much of twentieth-century biology, only to undergo a sort of renaissance at the start of the twenty-first. The story of why this should be so is complicated and fascinating, but belongs primarily to the history of biology. On the other hand, to the extent that it is so, a question naturally arises: what, after all, are organisms? This question has a long and complicated history of its own, both within and without of biology; an investigation (...) of this history yields some guidance as to how organisms might yet be conceived today. One suggestion borne of these investigations is this: organisms are, for better or worse, normatively delineated unities. (shrink)