Reality is a rather large place. It contains protons, economies, headaches, sentences, smiles, asteroids, crimes, and numbers, and very many other things. Much of the content of our reality appears to depend on other of its content. Economies, for example, appear to depend upon people and the way they behave, amongst other things. Some of the content of our reality also appears to be, in some significant sense, more important than other of its content. Whilst none of us would wish to deny the very important role that economies play in our lives, most of us would agree that without matter arranged certain ways in space, for example, there could be no economies in the first place.

Very many contemporary philosophers are concerned with how exactly we are to fill in the details of this view. What they are inclined to agree on is that reality has an over-arching hierarchical structure ordered by relations of metaphysical dependence, where chains of entities ordered by those dependence relations terminate in something fundamental. It is also commonly taken for granted that what those dependence chains terminate in is merely contingently existent - those things could have failed to exist - and consistent - they have no contradictory properties. This volume brings together fifteen essays from leading and emerging scholars that address these core, yet often under-explored, commitments.