Full Idea
When we look at our actions from the theoretical standpoint our concern is with their explanation and prediction. When we view them from the practical standpoint our concern is with their justification and choice.
Gist of Idea
Theory of action focuses on explanation and prediction; practical action on justification and choice
Source
Christine M. Korsgaard (Intro to 'Creating the Kingdom of Ends' [1996], §4)
Book Reference
Korsgaard,Christine M.: 'Creating the Kingdom of Ends' [CUP 1996], p.378
A Reaction
A nice distinction, which invites us to further subdivide action theory into two branches, with entirely different concerns.