Kindest Regards, Snoopy!
After 3 years of Abraham Maslow, I'm a bit burned out on "stages" of anything. I seem to recall having looked into Kohlberg out of curiousity, and was disappointed. Even in his own research I seem to recall a frustration that things did not develop quite as forecast. Perhaps the biggest disappointment was that none of his subjects who reached the highest level (6? or was it 7?) were able to maintain that level consistently. I seem to also recall some difficulty with one of the intermittant levels, that some researchers split and made contingent, and others did not. At any rate, I think Kohlberg points up some good developmental psych points, and little else.
As for Fowler, I see an attempt to use the Maslow / Kohlberg model to develop a structure, perhaps with merit and basis, depending on culture. I don't see a great deal of original thinking, simply a new way of compartmentalizing. William James is some interesting reading regarding the development of religion.