The most important recent development that falls within the scope of this meeting, "Language and Ontology", is the somewhat amorphous body of ideas, conceptualizations, and results which is best known aspossible-worlds semantics.¹ Its eminence is well founded. We consider it as self-evident as anything in philosophy that one cannot do justice to actual human experience without a conceptual system that includes possibilia. It does not suffice to speak of different objects, different properties, different relations, etc.; at some point we also have to speak of different things that can happen or could have happened. To put the same point in more vivid terms, our life is intrinsically and inevitably acted against a backdrop of unrealized possibilities. Jaakko Hintikka has articulated this idea by connecting the use of unrealized possibilia with the concept of intentionality in which several philosophers, notably Husserl, have seen the gist of human thinking, and outlined a theory of intentionality based on this relationship.²