In this paper, I explore the work of several positivists involved with the “Metaphysical Club” of Cambridge, Massachusetts in the early 1870s—Fiske, Wright, and Abbot. Like the logical positivists of the 1930s, these philosophers were forced to answer a key question: with so many of its traditional domains colonized by science and so many of its traditional questions dismissed as metaphysical or useless, what is left for philosophy to do? One answer they gave was that philosophy could unify the sciences. As Fiske put it, “positive philosophy is science organized.”