The past several decades bear witness to the emergence of a cause that has become tremendously, even wildly popular in contemporary scholarship. The cause in question is pluralism. We use the term “cause” rather than “concept” for two reasons. First, pluralism itself is a set of concepts; among our tasks is to explore the extent to which the varying concepts cohere, and in what ways. Second, we say “cause” because our focus is principally pluralism in psychology, within which pluralism is frequently encouraged or endorsed rather than merely analyzed in a distanced way on a conceptual level. We find that since the 1990s there have been many references to pluralism in psychology and explicit calls for psychology to embrace a pluralistic framework for reasons that are sometimes cast as moral in nature, suggestive of a cause and, perhaps, a therapy for the discipline (e.g., Goertzen & Smythe, 2010; Kirschner, 2006; Slife & Wendt, 2009; Teo, 2010a; Ussher, 1999; Viney, 2004; Wertz, 2011). As we will make evident in Chapter 2, promotion of pluralism or a pluralistic approach to psychology comes in many forms and appears in an array of diverse contexts.

In this final chapter, we summarize in brief the preceding chapters and offer reflection on what our project contributes and what escapes it, what it leaves undone.

In Chapter 1, we attempted to contextualize the many different appearances of pluralism across disciplines. In Chapter 2, we focused on its uses and definitions in contemporary psychology, mapping out various contexts and meanings associated with pluralism that have been offered over the past several decades. Then, in Chapters 3 and 4, we analyzed and discussed James’s definitions and uses of pluralism concepts. We also made clear that the term “pluralism” betrays a complex and intricate web of different yet intertwined concepts that extend at least to three distinct realms: the ontological, the epistemological, and the ethical. Now, based on all this review and analysis, we turn to a broad comparison of forms of pluralism in contemporary psychology and in William James. Our goal is to consider both how other authors have understood the implications of pluralism for contemporary psychology, and to analyze some features of James’s pluralistic philosophy for psychological metatheory that have not received detailed treatment in the literature. As a disclaimer, our intent is not to offer a map or model of what pluralism in psychology would look like in practice.

In Chapter 3, we tracked James’s references to “pluralism” across the course of his writing and correspondence. Doing so, we saw that James developed his pluralistic philosophy from his early essays in the 1880s through his psychological explorations in the Principles and Varieties and then into his most mature contributions. We believe that this developmental “tracking” is highly informative. By following his uses of “pluralism” in this way, noting where it appears, the intended purposes for which it is employed, and especially the terms with which it is associated and those with which it contrasts, it becomes clear that “pluralism” is a very complex notion or set of notions, acquiring subtly different meanings in different contexts.

Chapter 2 examined a range of meanings of pluralism evident in contemporary psychology, providing a reminder of the problems that can arise when we unreflectively treat concepts as consistent in meaning across time and disciplinary contexts. In this chapter, we turn our focus exclusively to the pluralism of William James, yet a similar cautionary note is in order. Although it is commonplace to speak of an author’s “concept of x,” upon scrutiny one may find meanings of “x” to be variable in different texts or across phases of that author’s thought. Therefore, this chapter aims to follow the development of James’s uses of the term “pluralism” across the body of his work, including his notes and correspondence. Among the goals of the chapter are (1) to consider how James’s early uses of the term “pluralism” relate to later versions, (2) to distinguish any divergences in meaning, and (3) to inquire whether there are consistent themes across his writing that pertain to pluralism.1

This chapter illustrates the variety, scope, and function of recent concepts of pluralism evident in contemporary psychological literature. With this broad survey, our purpose is both to support our claim that references to pluralism are widespread across psychology and to develop a basis upon which we might compare psychology’s concepts of pluralism with those evident across the work of William James, which we take up in the chapter to follow.