Abstract
Hilary Putnam’s wide ranging thought turned on an axis: an idea of the shape of an object of rational thought, a reflection of a rational being’s unbounded capacity for unprejudiced self-criticism. The idea unfolds in a particular way the motto “The conceptual cannot take care of itself.” No stock of concepts can derive their content merely from structural relations between them, no matter how complex. What more there is to content, on this unfolding, lies in a concept’s unbounded openness to world-dependence. This essay works through that idea in and through positioning Putnam in relation to two other great philosophers, Leibniz and Frege.