Judging mens rea: the tension between folk concepts and legal concepts of intentionality.

Concepts such as intention, motive, or forethought have generated a great deal of doubt, dispute, and confusion in legal decision making. Here we argue for an empirically based strategy of defining and using such mens rea concepts. Instead of the standard approach of settling these concepts by theoretical argument and the debaters' own intuitions, we rely on social psychological research to determine the meaning and significance of folk concepts concerning mens rea. We demonstrate the reliable and systematic use of people's concept of intentionality, contrast it with the bewildering variety of related legal concepts, and apply the folk model of intentionality to debated distinctions between intention and intentionality, desire and intention, and belief and intention. This folk-conceptual approach promises clarity of mens rea concepts and a reconciliation of the legal and layperson's view of human behavior. Copyright 2003 John Wiley & Sons, Ltd.