Abstract

Contemporary philosophers have overall studied intentional actions that agents attempt to perform in the world. However, logicians of action have tended to neglect the intentionality proper to human action. I will present here the basic principles and laws of a logic of action where intentional actions are primary as in contemporary philosophy of action. In my view, any action that an agent performs unintentionally could in principle have been attempted. Moreover any unintentional action of an agent is an effect of intentional actions of that agent. So my logic of action contains a theory of attempts. As Belnap pointed out, action, branching time and historic modalities are logically related. There is the liberty of voluntary action. I will then work out a logic of action that is compatible with indeterminism. In classical philosophical logic, propositions with the same truth-conditions are identified. However it is clear that strictly equivalent propositions are not the contents of the same attitudes of human agents. For that reason I will first present a non-classical propositional logic capable of distinguishing the contents of intentional actions which are different. Next I will enrich earlier logics of action so as to characterize adequately intentional actions, attempts and purposes of agents and the different kinds of generation of action. I will state the basic laws of agentive commitment and action generation