Cambridge change is a concept within metaphysics which differs from the ordinary conception of change. A Cambridge change occurs when a predicate P is true of object O at this moment (e.g. "Chicago is north of me") but is not true of O the next moment (e.g. "Chicago is south of me"), not because O's bodily constitution is no longer the same, but because some difference in the constitution of an object G (I have moved from Atlanta to Toronto) makes logically necessary the passage of the original predicate from true to not true.