What did William James mean by pluralism in philosophy?

For William James, pluralism was a philosophical stance that prioritized the diversity, changeability, and unfinished nature of the world over the concept of a unified, static "block universe."12

James utilized his pragmatic method to argue against monism—the belief that all reality is a single, interconnected piece—and rejected the idea that internal relations necessitate that one cannot have a single thing without having everything else. Instead, he maintained that the relations between things, whether they hold them together or separate them, are as real as the things themselves, requiring no hidden metaphysical substrata to explain the world's coherences and clashes.2

In his work A Pluralistic Universe, James emphasized that empirically minded thinkers must account for the multiplicity of things and their interactions. By championing pluralism, James sought to move philosophy away from static finalities and toward an understanding of a world that is in constant process, characterized by novelty, chance, and variety.12