One of Maharishi's famous quotations is "the proof of the pudding is in the eating". It is easy enough to argue about whether or not TM works or not. But until one tries it for themselves, it is only a semantic discussion.
Here is an explanation of the mechanics of Transcendental Meditation as I have understood and experienced them.
TM is based on 3 assumptions:
- given the opportunity, it is the nature of the mind to settle down
- given the opportunity, It is the nature of the body to release stress
- the mind and body are interconnected.
If the first two assumptions are accepted, then one can also see the mechanics of TM.
When "initiated", the meditator is provided with a unique, meaningless sound or mantra. I don't know how the mantra is chosen. In the Hindu tradition, mantra can be roughly translated to "chant" or "incantation", but I expect this is slightly inaccurate.
The mantra is specifically chosen because it bears no meaning to the individual. The individual is asked to introduce the mantra into their mind, just like any other thought, and then let go. The first assumption from above dictates that, as the mantra is introduced, the mind naturally begins to settle. The mantra acts as a vehicle to lead the mind into finer and finer levels of thought until there are no thoughts. This process is meant to be as effortless and natural as introducing a thought.
The state of consciousness into which the mind has settled down is a deep rest which has been labeled "transcendental consciousness". Significantly altered brainwave patterns show that the mind is in rest (like sleep state), but alert (like waking state).
When the mind settles down, the 3rd assumption dictates that the body will also settle down. And consequently, the 2nd assumption dictates that the body begins to release stress. Sometimes it does so easily, sometimes by physical movement. Either way, release of stress makes the body active again. And consequently, the mind becomes active again and thoughts arise.
When the individual realizes the return of thoughts again, he/she introduces the mantra again and the cycle restarts.
Disclosure: I attended MSAE for 8 years. I run the risk of being brainwashed with this knowledge, but so far I have not found any holes in it that I cannot explain. And if at some point I do fail to explain a phenomenon, I can still hang on to the fact that TM makes me feel good. At the end of the day, placebo effect or not, that is what really matters.