Mixed company moderates; like-minded company polarizes. Heterogeneous communities restrain group excesses; homogeneous communities march toward the extremes.
The best lines from and in-a-nutshell gist of The Big Sort by Bill Bishop.
more of what i like
a collection of things that caught my eye/ear/brain
see also:
mlarson.orgflickr
last.fm
blip.fm
etc.