A Constitution is a blueprint for any society; especially a new one. In order to build anything complex and substantial you need a plan. A plan that is more than a scribbling on a cocktail napkin. It is one thing to profess an idea or philosophical theory but another to actually build it. A constitution is the specifications of how that idea is to be constructed and maintained. It is a boundary document used to keep a society from straying away from the principles it was founded on. The better the boundaries are clearly defined the easier it will keep society from contorting it.