This book discusses the main problems, tenets, assumptions, and arguments involved in Charles S. Peirce's early and late realist stances and subjects to critical scrutiny the still dominant view that Pragmatic Realism merely extends or refines new arguments in support of Scholastic Realism without questioning its basic assumptions. The book presents a critical overview of Peirce’s views on modern nominalism and offers a novel approach to the social-anthropological underpinnings of his realism, especially Pragmatic Realism vis à vis the individualist tendencies in modern thought.