For seven decades Charles Hartshorne has presented his philosophical themes with ingenuity and deep historical awareness, comparing his positions in illuminating fashion with those of major figures from Plato to Kant to Popper. Integral to Hartshorne's thinking have been bold, fresh interpretations of such notions as God, freedom, change, creativity, aesthetic meaning, the social character of experience, and generalized causal possibility with a place for probabilities and open possibilities.