Gall's Law

Gall's book (Systemantics) is a brilliant and whimsical classic about the unpredictable nature of complex systems. It deserves to be far better known.

Simple and complex are relative terms. What a highly educated person anno 2009 would find simple might be complex to a uneducated person anno 1009.

Which implicates this "law" is also relative, making a more useful description: If you make something which seems complex to you, it will not work. Begin with something that is simple to you, and than evolve it in to something complex.

Summary: the law says "A complex system that works is invariably found to have evolved from a simple system that worked. The inverse proposition also appears to be true: A complex system designed from scratch never works and cannot be made to work. You have to start over, beginning with a working simple system."

This is obviously closely related to Richard Gabriel's "Worse is Better", and the general philosophy of starting with a simple design, and iterating under the scrutiny of users.

That "inverse proposition" is just the contrapositive: (a => b) <=> (¬b => ¬a).

The inverse proposition would be that if you take a simple system that works and evolve it into a complex system, the complex system will work.