Modality

This article attempts to move the heart of any reader whose initial inclination is to share Bradley's evaluation of the subject of modality. It may be too much to hope that such readers will be wholly won over to this article's opinion on this matter, namely, that philosophy departments of a broadly analytical stripe - or at least their graduate schools - would do well to post an inscription resembling that said to have greeted those at the gates of Plato's Academy: 'Let no one who is ignorant of modal logic enter here.' Although one might expect the philosophical interest of modal logic to lie mainly in the area of modal predicate logic, what follows mostly concerns propositional modal logic, which will already provide ample food for thought - even though many issues of interest will for that reason not get discussed.