Conditionals are expressions of the form if ... then ... Particular instances are counterfactual conditionals (``if it were the case that A then it would be the case that B''), causal conditionals (``if A then causally B''), action conditionals (``if A then B is obtained''), conditional obligations (``if A then B should be brought about''), generic conditionals (``if A then normally B'') etc. The commom pattern to all these constructions is their conditional form which connects the antecedent to the consequent in such a way that the antecedent represents a condition (or a context) for the consequent. The general question is whether it is possible to give a formal logical account of these constructions.
It has been much discussed whether it is justified or not to treat an action or a cause as a proposition. In particular in dynamic logic, the conditional is expressed by a formula [a]B, where a is an action (or a program) and B is the proposition expressing the result of the action. This relates to our reasoning about actions research topic.
In turn, if one considers the consequent and the antecedent of a conditional as propositions, the analysis of the conditional is reduced to the characterisation of the formal link between them. It has been recognized quite early that the truth conditional account that classical logic is far from being adequate to formalize such constructions. Such a link corresponds to an intensional (and thus modal) structure.
Our research on conditionals is based on the Stalnaker-Lewis possible worlds analysis. We are interested in