A Definition of Permaculture

"Perfection is not when there is no more to add, but nor more to take away."
- Antione De Saint - Exupery

I have been studying and working with permaculture design for the better part of 10 years. Not long I know, but long enough think. With each new experience and new piece of relevant information my opinion and understanding of permaculture has changed. In the beginning I was driven by hard line social and political perspectives. Over time I have matured and mellowed focusing on the pragmatic rather than idealistic side of things. My understanding of permaculture has moved away from sweeping dictates regarding social and cultural change, towards the reality of on the ground problems regarding the: sensible design of landscape, economic balance sheet of those designs, and, most importantly, goals of my clients and students regardless of how they personally feel about plastic or owning a car. This necessary shift in perspective has come along with the development of a concise and testable definition of permaculture.

Permaculture:

An integrated site adaptive design process that maximizes human goals while maintaining ecosystem function.

It is often said of permaculture that it is: "undefinable" or "not just one thing but many" or "the longer your work with the less you know about it" and on and on. Permaculture has come to mean many things to many different people. While this ambiguity is effective at creating the brand mystic of permaculture, it is not effective when it comes to reality of implementation across different contexts and between competing interest. Most definitions of permaculture are broad and subjective and amount to little more than a moving set of goals posts, which can be conveniently adjusted to meet the flavor of the month. I have never been satisfied with this. I think a definition by which the results of our actions can be tested is needed. Such a definition of permaculture will go a long way to improve credibility within "mainstream" society and help move permaculture towards the professional realm.

Maybe the professional fields of: engineering, architecture, landscape architecture, agronomy, agro-ecology, hydorology...ect are enough?
Maybe permaculture is redundant?
Maybe permaculture's proper place is as a special interest fringe "movement"?
Maybe permaculture is not necessary?

At this point I don't know and doubt anyone does.
I do know that having and applying a testable and accountable definition will be an important part of the answers.