Timothy Leary (1920-1996) was a psychologist, academic, and writer best known as an advocate for the use of psychedelic drugs. Leary's controversial work with the Harvard Psilocybin Project helped get him fired from Harvard in 1963. He later became a counter-culture icon and was even once described by Richard Nixon as "the most dangerous man in America." Leary died of prostate cancer in 1996.
"In the information age, you don't teach philosophy as they did after feudalism. You perform it. If Aristotle were alive today he'd have a talk show."
-Timothy Leary, as quoted in The Best Advice Ever for Teachers (2001) by Charles McGuire and Diana Abitz, p. 57 (h/t WikiQuote)