adjective: A much needed neologism, applied to all forms of degenerate, artificial, Californian spirituality.
Trashendental thinking is basically about feeling good without paying for it, that's to say, experiencing Zen illumination without the Zen discipline, feeling elated by Gregorian chant without really understanding the robust (and hateful, at least to me) worldview behind it.

Thought systems come with strings attached. Trashendentalism is about ignoring those strings, and trying to get at the fuzzy, warm (and currently convenient) part of the system.
Or getting all hot and bothered about the Aztecs. A bunch of people that practiced war, cannibalism and mass slaughter on a rarely paralleled scale, they are nonetheless painted as the great Mexican spiritual ancestors.
And what about the Indians (Native American, Redskins, whatever you choose to call them) in the US ? Trashendentalists like to paint them as saints and wise, earth loving, caring people. Well, maybe they are now, but in their time they completely wiped out the American megafauna, during just one thousand years of happy hunting. And they did know (and appreciate) war (the Iroquois even had a fine aesthetic vision of torture) - of course, this is just a sweeping generalization, there were many tribes and visions and thought systems, my point is that you cannot simply talk about Native American, you have to be more specific.
One of the greatest purveyors of trashendental thought ever (and I know this is gonna cost me) was Herman Hesse, and generally speaking the Orientalism crowd.

How to detect trashendental thought ? Easy:

  1. it is thoroughly pleasant
  2. it is about feeling good rather than doing good
  3. it is remarkably free of obligations
  4. it has been ripped free of its roots

You may ask, "But what is the problem, if it makes me feel good ?". Well, I would answer that spiritual solace bought cheap (maybe at the price of a few flavored candles, some cross legged sitting) is indeed cheap, which means that it will snap under stress - when you most need it.

I remember seeing an American (as in US) woman doing trashendental meditation in the Monte Alban ruins, sitting in zazen in the very spot where there the sacrifice altar was ... now, the setting might have look nice and green and there was an attractive symmetry in the architecture, but I suspect that she was sitting at the focus point of all the bad karma in a 10 kilometer radius (if there is such a thing).

Another chief characteristic of trashendental thought is that it likes broad categories like Native American Culture, Indigenous People, Chinese Wisdom, Medieval Spirituality, and does not look into the fine structure.
If you just take a short look into (for example) Chinese thought, you will find an amazing amount of schools and visions, contrasting and fighting. Is there such a thing a Chinese wisdom ? I doubt it. Chinese wisdoms would be more like it. But then you would have to choose betwenn those wisdoms, and understand your choice. And doesn't that hurt ?
One could probably sum it up by saying that trashendental thought is kitsch in philosophy (or religion). Grabbing only some elements, magpie-like, it presents building that are adorned with red paper balloons, crenellations and little papier maché volcanos.
<Overcooked pasta with soy sauce is served inside.

Anyway, much like in alcohol, you choose your poison.
Trashendental thought is like a watered down martini in a plastic carafe, drunk in Florida. Comes with a colorful little plastic umbrella.