My aim in what follows is to sketch with a broad brush fundamental changes involving the concept of obligation in British ethics of the early modern period, as it developed in the direction of the view that obligatory force is a species of motivational force – an idea that deeply informs present thought. I shall also suggest, although I can hardly demonstrate it conclusively here, that one important source for this view was a doctrine which we associate with Kant, and (...) which it may seem surprising to find in British ethics, especially of the early modern period, viz., that rational agents are obligated by motives available through a form of practical thinking necessary for rational autonomy. (shrink)