"ANY situation or action or behavior...etc. that has no practical limitations will usually get out of hand."

I have to agree with that - and yet the concept of the bottomless pit/pot-of-infinite-capacity seems to be one on which most social policy and economic theory is be based. I quite like living in a diverse society, and in many ways I consider that another person's ethnic background is none of my business and should not affect the way that I deal with that person on a day-to-day day basis. But I am aware that high population densities can lead to dangerous tensions building within society. Politicians and decision makers cannot just assume that allowing the population to keep on growing (by whatever means) has no consequences and can be ignored. One consequence is, of course, that people from an obviously different ethnic background to the majority population make obvious scapegoats for fascists like the BNP.