 The principles for the (proper) part-of relation imply that complexes with the same parts are identical. But take the state of affairs that Romeo loves Juliet. If it has Romeo, Love and Juliet as its parts, it is the same as the state of affairs that Juliet loves Romeo. But intuitively, the state of affairs Juliet’s loving Romeo is different from the state of affairs Romeo’s loving Juliet. On the standard mereological conception of part, particulars and universals are not parts of states of affairs.