Toward a Useful Concept of Causality for Lexical Semantics

We do things in the world by exploiting our knowledge of what causes what. But in trying to reason formally about causality, there is a difficulty: to reason with certainty we need complete knowledge of all the relevant events and circumstances, whereas in everyday reasoning tasks we need a more serviceable but looser notion that does not make such demands on our knowledge. In this work the notion of'causal complex' is introduced for a complete set of events and conditions necessary for the causal consequent to occur, and the term 'cause' is used for the makeshift, nonmonotonic notion we require for everyday tasks such as planning and language understanding. Like all interesting concepts, neither of these can be defined with necessary and sufficient conditions, but they can be more or less tightly constrained by necessary conditions or sufficient conditions. The issue of how to distinguish between what is in a causal complex from what is outside it is discussed, and within a causal complex, how to distinguish the eventualities that deserve to be called 'causes' from those that do not, in particular circumstances. One particular modal, the word 'would', is examined from the standpoint of its underlying causal content, as a linguistic motivation for this enterprise.