This is the great era of shamanism, and what is shamanism but philosophy with a ‘hands on’ attitude?  Philosophy not made around a campfire, but philosophy based on the acquisition of extreme experience.  That’s how you figure out what the world is.  Not by bicycling around in the ‘burbs, but by forcing extreme experience.  The reason people refer to psychedelic endeavors with the vocabulary of travel—taking a trip and so on—is because that is an extreme endeavor.  It’s the same endeavor.  It’s the leaving behind of the values of your own culture.  Take nothing but a change of clothes, fly to Benares, and take up residence at Dashashwamedh Ghat among the Charas Shaivites, and I guarantee you, whether you resort to psychedelics or not, you will experience boundary dissolution, a reorientating of categories, and a reframing of your perspective on your life and your being.  So extreme experience is the necessary key.  This is true in all forms of endeavor.  If you want to understand the atom, you have to smash it.  Sitting around looking at it, it will never yield its secrets.  You have to smash that sucker to bits and then collect the pieces and then examine exactly how it all came apart.  In the same way, and without going too far afield for the pun, we must smash ordinary consciousness—get smashed—and then look at the pieces flying in all directions.
—  Terence McKenna