Darwin’s revolutionary arguments for the transformation of species emerged against the backdrop of a century-long transnational debate over the nature of organic species. The aim of this chapter is to clarify this context and relate it to Darwin’s Origin.

Following a brief summary of the “species problem” in the period before 1850, I analyze some key aspects of Darwin’s species concept in the so-called Big Species Book (1856-58) (Species Book) that directly underlies the published Origin. This will be followed by a discussion of Darwin’s public presentation in the Origin, followed by some brief remarks on the divergent interpretations by Darwin’s successors.

THE SPECIES QUESTION BEFORE 1850

Available literature on the history of the species concept (Bachmann 1906; Uhlmann 1923; Stamos 2003 and references therein) only partially clarifies the nature of the debate over organic species in the period before the Origin. Anglophone discussions typically take as their reference framework British, or to a lesser degree French, natural history, assumed to be the main relevant background against which to assess Darwin’s own reflections.