 What did Darwin mean by the word ‘species’? Answers to that question vary (see Ghiselin 1969, Mayr 1982, Beatty 1992, Stamos 2007, Mallet 2008, Kohn 2008, Wilkins 2009, and Ereshefsky 2010c). Nevertheless, it seems that Darwin was an anti-realist when it comes to the species category, though a realist concerning those taxa called ‘species’ by competent naturalists. Consider what he wrote to his friend, the botanist Joseph Hooker.