In the volume of The Library of Living Philosophers ¹ devoted to his philosophy, von Wright writes that most of what he has written could perhaps be classified as "philosophical logic". However, when it comes to dividing different themes on which he has been writing, von Wright follows what I think is more or less the prevalent terminoly and puts under the heading "philosophical logic" themes such as logical truth, entailment, modal logic, the logic of time, deontic logic, preference logic, and counterfactual conditionals. I shall follow this terminology except that, for reasons that will soon become clear, I shall not count the theme of logical truth as particularly belonging to philosophical logic.