I was browsing through Google books one evening looking for some works on unity, ecumenical unity that is. I came across a work by David J. DeLeonardis, Ethical Implications of Unity and the Divine in Nicholas of Cusa.
Cusa's notions of unity are rooted first and foremost in Being. Being and unity exist in a dynamic relationship because each entity that exists is a contraction of all Being, making for a facinating notion that while individuals are unique, they are also dynamically connected to all others since each individual stems from the same source, God. DeLeonardis writes, "Through contraction each being becomes ontologically linked to every other being since all entities derive their being from a common source."
Cusa's notions might help our notions of unity, since his is not one of a monolithic homogeneity, rather a harmonious diversity.