Abstract
The relation between leibniz's logical and his metaphysical views is the subject of much modern scholarship. Some commentators have argued that his metaphysics is based on his logic; others have taken the opposite position. However, Both sides pose the question in terms of 'priority'. On the contrary, I argue that it is likely that leibniz means the psr to play "both" a logical and a metaphysical role. The ambiguity of leibniz's psr indicates that he equates the metaphysical notion of causation with the logical notion of deduction. The psr's ambiguity results less from any confusion on leibniz's part between the notions of cause and reason, Than from his desire to identify logic and metaphysics. That identity is achieved not by reducing one to the other, But by incorporating them on an equal basis into a single discipline