Loosely coupled parts is a maxim of those who build re-usable and open processing systems. Loose coupling is also a feature of natural or naturally evolved systems.

To start, consider Small Parts Loosely Joined: A Unified Theory of the Web (Weinberger, 2002), an interesting treatise on the manner in which the world wide web is constructed, as is the Internet - the technological substrate on which the web is constructed. Weinberger is a pretty smart guy but he gets no credit for having noticed the web's construction technique, let alone inventing it. What he is doing in his book is a good job of explaining why the approach works. It has been a while since I read it so I can't quite remember if he noticed that open societies function analogously - or rather: the Internet and the Web function analogously to open societies.

Each of the parts in a loosely coupled system expresses an agency that serves both themselves and the system within which they operate. There are open standards (protocols) that control interactions, but we're getting better and better at loosening the joining mechanisms. This accounts for the wild growth of the Internet