Philosophers approach the problem of possibility in two markedly different ways: with reference to worlds, whereby an event is possible if there is a world in which it occurs, and with reference to modal properties, whereby an event is a possible manifestation of a property of some substance or object.Showing how the world-account cannot properly explain the nature of possibilities within worlds, Ferenc Huoranszki argues that the latter approach is more plausible. He develops a theory of contingent possibilities grounded in a distinction between abilities and dispositions as real, first-order modal properties of objects, with fundamentally distinct ontological roles. By understanding abilities as first-order modal properties, and by linking such modal properties to counterfactual conditionals, Huoranszki argues we can distinguish between variably generic or specific abilities and identify more or less abstract possibilities in a world. In doing so, he furthers our understanding of how we reason with possibilities in both ordinary and theoretical contexts. Providing a novel account of dispositions, abilities and their capacity to explain modality, this book advances current debates in contemporary metaphysics.