The nature of the 'spiritual teacher'/'disciple' dyad makes impossible to do any sort of scientific examination to see if the teacher's claims are true or actually help people.
John Wren-Lewis was a scientist and found himself in a state nondual realization as a result of a medical crisis.
He wrote an article entitled Lotus Feet of Clay
Wren-Lewis contended that that guru/spiritual teacher role created a pattern of social relationships that actually militated against any objective, unbiased inquiry into the nature of enlightenment itself -- the very thing that gives gurus their authority and their demand for our submission to their authority.
In the atmosphere of reverence and deference that surrounds spiritual teachers, their claims to be enlightened and whether enlightenment was permanent or an impermanent state, go unquestioned and uncorrected.
Wren Lewis particularly wished to know whether enlightenment could be permanent or whether it tended to come and go.
Wren-Lewis noticed that he was capable of drifting out of this experience, and that it was not permanent., that he could get impatient and crabby, though once he recognized this, he could return to nondual realization.
But as Lewis put it, because he wasnt in the role of master, people felt free to call him on his stuff.
"This was of course another issue on which I initially hoped for some help from mystical writings or a spiritual movement: was there anything I could do, like meditation or diet, to reduce the frequency of drifting out?
'I was extremely puzzled when my research turned up almost no reference to any such possibility.
'Krishnamurti is the only spiritual teacher I know whose writings hint at experiences similiar to mine in this respect; everywhere else, it's taken for granted that one is either a disciple on the path, practising meditation or guru-darshan or whatever to reach God-consciousness, or else a Master who is supposed to be in it permanently
."((And it is from this supposedly permanent state at-one-ment that the masters get their prestige, their authority and people keep showing up at their events or buying thier stuff, hoping some day to realize permament enlightenment themselves. C))
'The total silence about the drifting-out which I experience daily seemed highly suspicious. I was therefore very interested to come upon Agehananda Bharati's important book The Light at the Center
, in which he asserts quite categorically that "permanent enlightenment" is only a conventional fiction of the guru-system, possibly never actually realized, but maintained in order to foster the total surrender which is believed essential for the system to work.
 Agehananda Bharati, The Light at the Center
(Santa Barbara, CA: Ross-Erikson, 1976).
"The trouble is that once such a system is swallowed, the guru cannot admit to lapses without completely discrediting his claim to have any enlightenment to pass on."
"Even worse, there is a tendency for the wish to spread the Word to pass over into the most insidious of all power-trips, with the Master thinking of himself as God rather than vice-versa, the phenomenon Jung called inflation. know about this from personal experience But because I'm not claiming to be a Master, no-one gets sucked in and I'm soon forced to come off it.
'When the Master-disciple relationship has been established, disciples have to go along with the Master's rationalizations or abandon the hope they've placed in him.
"And from the wider human point of view, I believe the closed, self-confirming guru-system has an even more important defect, even with Masters who manage to avoid such temptations, namely that there is little or no opportunity for theories and techniques to be evaluated against their experiential results and exchanged for better ones.
Wren-Lewis referred to one guru who was much in the news at the time.
'I have no idea what this discrepancy between my experience and Maharishi's theory means, since I've yet to find any of his disciples who've "gotten that far," and he himself remains hidden behind the Master-role, unavailable for discussion.
'Is he reporting firsthand experience in some way different from mine (maybe more advanced), or has he adapted his God-experience (which I'm sure he's had) to fit traditional yogic theory?
"The Master-system prevents such questions from being investigated. "
For the master system itself cannot be questioned--without the questioner being accused of having ego problems!