The Many Faces of Realism

Conceptual relativity is the claim that a situation can be described correctly in more than one way, using vocabularies that cannot be reduced to a single privileged one, and that the answer to what exists depends partly on the description adopted. Putnam illustrates it with a toy world containing a few individuals, where the number of objects differs depending on whether one counts only the individuals or also their mereological sums. He argues that neither description is the one true account. Critics, particularly those defending a single privileged ontology, have asked whether the examples show a difference in the world or only a verbal difference in how we speak.

Putnam insists that conceptual relativity is not the claim that anything goes. Once a description is adopted, what is true under it is not up to us, and some descriptions are better or worse for particular purposes. He also denies that truth is simply what a community agrees upon. What he rejects is the metaphysical realist's further demand that one description must capture the world as it is independently of all conceptual contribution. Critics have pressed him on whether this middle position is stable, and some, including Donald Davidson, resisted the very idea of conceptual schemes that the doctrine presupposes.

Putnam presents his view as continuous with a line of thought running from Kant, who held that our concepts contribute to the structure of experience, but he rejects Kant's noumenal world of things in themselves as incoherent. The lectures also revisit earlier philosophers to show how the demand for a single, complete description recurs in different forms. These historical readings serve the systematic argument rather than aiming at scholarly completeness, so specialists in the figures discussed may find the treatments selective. They are best read as Putnam's account of his own philosophical genealogy.

Reason, Truth and History presented internal realism through the brain-in-a-vat and model-theoretic arguments, and tied truth to idealized rational acceptability. The Many Faces of Realism refines the position by adding conceptual relativity as a way of explaining why there can be no single, scheme-independent description of the world. It also explores more explicitly how the view bears on ethics and on the plurality of ways of describing the same facts. Readers who want the arguments for internal realism should begin with the earlier book, then turn here for the doctrine's compact restatement.

Putnam later grew dissatisfied with internal realism, regarding it as still too close to the picture of an interface between mind and world that he came to reject. In The Threefold Cord and related writings he moved toward a natural realism in which perception reaches the world directly. He nonetheless retained conceptual relativity, and returned to it in Ethics without Ontology. The book is therefore best read as a stage in an evolving position, not as his final word, and its claims should be compared with those later statements.

The plural in the title leads some readers to think Putnam endorses many incompatible realities, or that reality is whatever a scheme says it is. His claim is narrower: that realism admits more than one correct way of describing the same world, and that the demand for a unique description is a philosophical prejudice. He maintains that truth remains answerable to how things are and that mistakes are possible. Reading the book as relativism or idealism overlooks this commitment to objectivity within descriptions.