Chapter 1: This chapter starts by tracing the development of objectivity in both science and theatre through classical and early modern theatre, in which it was a fairly unimportant epistemic virtue, into the late eighteenth century where objectivity begins to emerge through the idealizations of ‘Truth-to-Nature’ in biology and in literary and theatrical Romanticism. Although some conceptions of scientific objectivity and observation treat these as virtuous by the extent to which they rise above personal or historical bias, the practice and theory of both objectivity and observation have changed through history. Drawing on the work of Lorraine Daston and others, the chapter goes on to show that the emergence of modern (‘mechanical’) objectivity, and a new relationship with observation, mark both nineteenth-century science and Naturalist theatre. Making the comparison explains some of the antitheatrical claims of Naturalist authors and the contradictions of Naturalist practice. As nineteenth-century ‘objectivity’ is superseded, so the theatrical figuration of science gravitates towards areas of ambiguity, chaos, and indeterminacy.