The contrast flaunted in the title of this colloquium, "Explanation and Understanding",¹ is predicated on an important assumption. This assumption is best known as Brentano's thesis. It says, roughly, that there is an irreducible conceptual difference between two kinds of phenomena which I shall refer to as intentional and nonintentional phenomena. The non- intentional or physical phenomena are subject to explanation, the intentional ones to understanding.