My understanding of the whole principle idea in MD changed a lot in the years I´m here, so does my RL. It´s hard to say for me what is the "best" or "favorite" of mine because I consider myself a part in all of them differently at various times. If there would be a "principle of change" or one that fits closest to that I would choose it. But I cannot clearly see it, so I have to choose the one which fit best at the moment.
Principle of Syntrophy
Why?
Mostly because it stands for this:
"The Principle of Syntropy is the basis of clear-sightedness, prediction, intuition, healing, growth, some regeneration forms and some forms of annulment of destruction based on energy consumption."
(taken from http://md-archives.com/articles/principle-of-syntropy.html)