I have been talking to Jane about the provisionally named Unity project and we have decided that Harmony is a better title. I think that the search for le seul mot juste is almost always worthwhile. I wasn't happy with unity as, to my mind, its intimation of unbroken completeness is the last thing that I am trying to convey.
You can live in harmony without unity, which reminds me why I don't like tolerance. For me, tolerance carries the unmistakable tang of permission being granted. I don't think its up to us to grant permission to our neighbours. (This distinction - by the way - goes to the heart of my difficulty with the current UK government legislating things that are none of its business.)
I prefer respect to tolerance, and thus harmony to unity.