My wife and I founded a democratic school in Brussels, Belgium, some five years ago. Some basic principles of the school are freedom of choice, democracy, intrinsic motivation, interaction (more on this link). It's not funded or even recognised by any government because we do not, nor do we want to, comply with the standards of the subsidised school system. I've started to make a permaculture based design for the school, and again diversity is a key element for the success of it. Our school system works best when members of the school community have very different backgrounds and ideas, hobbies, interests. Students learn by exchanging information between them, so the greater the diversity within the school, the more knowledge and skills are passed on.
The biggest threat for the school is the government, however. Their ideal is uniformity: every student needs to have exactly the same skills and knowledge as every other peer at exactly the same period in life. Any exchange not coming from the teacher is not valued or is even simply not allowed. Play is considered a complete waste of precious time. Everyone not corresponding with the ideal is labelled: autistic, dyslexic, hyperactive, or just plain and simple stupid, and is often directed toward the exit.
Many initiatives trying to respect humanity and value diversity are crushed. Here in Flanders (north of Belgium) we are relatively left in peace by the government, but in Wallonia (south of Belgium), the Netherlands, Germany, Denmark and other countries, initiatives like ours are actively prosecuted. This convinces me even more to place Diversity with the ethic principles, as a conditio sine qua non for a healthy community. Only if we care for eachother, for our environment, for a fair share for each, ànd value diversity, can we move forward in our evolution toward a peaceful and joyful community.