Abstract

Many predicates are dispositional. Some show this by a suffix like "-ible", -uble", or "-able": sugar is soluble in water, gasoline is flammable. Others have no such suffix and don't wear their dispositionality on their sleeves. Yet part of what it is to be solid is to be disposed to resist deformation, and part of what it is to be red is to appear red to normal human observers in normal lighting conditions. However, there is no agreement as to whether dispositional predicates may be given a realist interpretation. For many authors, propositions containing them are made true by states of affairs (or facts) containing categorical, rather than dispositional properties. Many also claim that the states of affairs that make true attributions of dispositions to macroscopic objects are microscopic states of affairs concerning their parts. For example, what makes a vase fragile is the microscopic structure of its molecular constituents, which is what makes the vase break when it falls. Against these claims, I will argue that what makes a dispositional predicate apply to an object, whether macroscopic or microscopic, whether in common sense or science, is the object's having what I will call a powerful property. If the object is macroscopic, it is another matter whether the property is microreducible. My reasons for supposing that these powerful properties exist are those for postulating theoretical properties generally: they unify existing explanations and suggest new ones.