Besides the "Big Three" classical pragmatists, there were many other important thinkers labeled (sometimes self-identified) as pragmatist. George Herbert Mead (1863-1931) was particularly influential during the first several decades of the twentieth century, especially in his work on the social development of the self and of language. A generation later, Clarence Irving Lewis (1883-1964) wrote several significant works in the middle third of the twentieth century on what he termed "conceptualistic pragmatism," stressing how pragmatic grounds shape the interpretation of experience. His contemporary, Alain Locke (1885-1954), blending the thought of earlier pragmatists with that of W.E.B. DuBois (1868-1963), produced a large body of work on the social construction of identity (particularly focusing on race) and advocating cultural pluralism within the context of what he called a philosophy of "critical relativism" or “critical pragmatism.”
Another important thinker, often labeled as pragmatist, but noted more for advocating an explicit version of philosophical idealism, was Josiah Royce (1855-1916). Though there were other American idealists (e.g., G. H. Howison of the St. Louis Hegelians and Bordon Parker Bowne (1847-1910), known for his view of "personalism"), Royce is recognized as the most influential of them. Epistemologically, Royce noted that any analysis of experience shows that the fact and, indeed, very possibility of error leads to the postulation of both mind and external reality, since only minds can be in error and being in error presupposes something about which mind can be mistaken. The recognition of error presupposes a higher level of awareness, since knowing that one is in error about X presupposes that one recognize both X and what is mistaken about one's judgment. Error, then, presupposes some form or level of veridicality. Much like the story of the blind men who come upon an elephant, each believing that part of the elephant captures the whole, the message here is that error is really partiality, that is having only partial truth. For Royce, this also pointed to the ultimate communal nature of all interpretation, as knowledge (even of one's self) comes from signs, which in turn require some kind of comparison and finally of community. Royce extended this view, and displayed definite affinities to pragmatism, in his analysis of meaning. The meaning of an idea, he claimed, contained both an external and an internal element, much as we say that terms have both a denotation and a connotation. Ideas have external meaning in the sense that they connect up to an external world. But they have an internal meaning in the sense that they embody or express purpose. What is real, Royce claimed, is "the complete embodiment in individual form and in final fulfillment, of the internal meaning of finite ideas." As these in turn require comparison and moving beyond partiality, they come finally to a complete and coherent absolute level of ideas, what he termed "Absolute Pragmatism.