This chapter closes the first part of the book by presenting the first thorough account of the way in which a single case study exemplifies all of the elements which constitute integrative promise. Much recent biological literature has strenuously argued for the utility of traditional, observational natural history, especially as confronted with contemporary molecular phylogenetic methods. I argue here that the best way to understand the state of play around this question is to see it as a disagreement over the actual or potential integrative promise of natural history. According to some, natural history is key for integrating extant bodies of biological theory in response to the global biodiversity crisis; for others, different parts of biology or ecology will play this role. Integrative promise thus helps us understand numerous features of an otherwise somewhat perplexing “debate.”