It is tempting to say from the contemporary point of view that thePort-Royal Logic is full of confusions as well as insights. I have focused on several of these confusions and their relations, in particular the confusions between complex idea and proposition, between proposition and judgment, and especially between name and predicate. In particular I have tried to emphasize the instability of the Port-Royal semantics — the ways in which their theory of terms vacillates between earlier views and something closer to a modern analysis. It may, however, be more profitable to regard this work as incorporating several logics, and to view the confusions as the inevitable results of the dynamical tensions among these different views.