In this thread I am reminded of the Vulcan philosophy of IDIC. Infinite diversity in infinite combinations. Basically it is a shorthand version of saying that although people, cultures and species are vastly different from each other, they are all needed to make the world. One should not try to make everybody like himself, one should treasure differences in other people and trying to figure out how everybody with everybody's differences can all work together for the greatest good of the people as a whole.
All I know is it seems to work very well for my best friend and his wife, who are about as different as you can imagine but seem to work well together. Each of them has strengths that make up for the other's deficiencies.