Unity and Time in Metaphysics

The contributions to this collection deal with the fundamental problem of unity, which plays a decisive role in many contemporary debates (even when this role is not acknowledged). Questions like whether there can be unities that persist through time ? e.g. persons who remain the same throughout their lives ? are discussed from various perspectives. Is such an idea possible at all, and if so, what role do concepts like force, capacity, and disposition play in this context?