"This book on the frames of reference is based to some extent on my own thoughts and opinions. In some spots it may not be directly in line with the original texts, because my primary aim has been to get to the heart of the matter so that it can be conveniently put into practice. Those who hold zealously to the texts may feel that what I have written is wrong; but as for me, I feel that whoever is able to practice in line with what is written here will find that it can be taken as a guide to the true principles of concentration, discernment, and release. To hold to the texts isn't wrong, but they should be held to discerningly, just as in medicine: A doctor who thinks that the only way to cure a fever is to drink a concoction of boiled neem and quinine leaves is wrong. Some doctors may add the leaves of other trees and make it into a powder; some may make a concentrated extract; others may vary the dosage. In the same way, when practicing the Dhamma, to go no further than the texts may in some cases be wrong. Actually, any path that abandons defilement and brings relief from suffering is right. The value of medicine lies in its ability to cure disease; the value of a method of practice lies in its ability to abandon defilement. As far as I can see, there is nothing wrong with any method that has been found to work. In the end, all such methods must follow the basic principles of virtue, concentration, and discernment, and differ only as to whether they are crude or sophisticated, direct or indirect, fast or slow"
Taken from the introduction to "Frames of Reference" by the late Ajaan Lee http://www.accesstoinsight.org/lib/thai/lee/frames.html
. For me this sums up the spirit of the forest tradition Ajahns.