“The best mind-altering drug is truth.”

“Drugs and terrorism are both mind-altering and deadly.”

“Mental states such as loneliness, compulsion, anguish, attachment, pain, and faith are not just "all in the head" but in the brain as well. Brain, mind, and body are a continuum. Our thoughts—intention, fear, images, suggestion, expectation— alter the brain's chemistry. And it works both ways; thoughts can be altered by changing the brain's chemistry with drugs, nutrients, oxygen. The brain is hopelessly complex.”

“The greatest discovery of any generation is that human beings can alter their lives by altering the attitudes of their minds.”

“Drugs are a bet with your mind.”

“Religion is like drugs, it destroys the thinking mind.”

“The greatest discovery of our generation is that human beings can alter their lives by altering their attitudes of mind. As you think, so shall you be.”

“Science progresses best when observations force us to alter our preconceptions.”

“To run 100 miles and more is to bring the body to the point of breaking, to bring the mind to the point of destruction, to arrive at that place where you can alter your consciousness. It was to see more clearly. As my yoga teacher would say, “Injuries are our best teachers.” I'm convinced that a lot of people run ultramarathons for the same reason they take mood-altering drugs. I don't mean to minimize the gifts of friendship, achievement, and closeness to nature that I've received in my running career. But the longer and farther I ran, the more I realized that what I was often chasing was a state of mind — a place where worries that seemed monumental melted away, where the beauty and timelessness of the universe, of the present moment, came into sharp focus.”

“Let us accept truth, even when it surprises us and alters our views.”