A thing has a disposition to become F in a situation G if it is such that were G to come about, it would become F. Dispositions, potentials, or powers are thus certified by the outcomes that would arise in specified circumstances. Dispositional properties are frequently contrasted with categorical ones, thought of as underlying them, and permanently present, whereas dispositions are only realized or manifested in the circumstances specified. Thus a chemical substance is soluble in water if it is such that, were it placed in water, it would dissolve, and the categorical basis of this disposition will be the nature and configuration of its molecules. This way of thinking accords better with a corpuscularian or atomistic philosophy than with modern physical thinking, which finds no categorical basis underlying the notions like that of a charge, or a field, or a probability wave, that fundamentally characterize things, and which are apparently themselves dispositional. The distinction between dispositional and categorical properties is also threatened by the reflection that even solidity and shape, perhaps the best candidates for categorical properties, seem susceptible to a dispositional treatment: solidity in a body is its disposition to exclude other bodies from the region of space that makes its shape. See also counterfactual conditional, finkish.