Dennis McKennaDennis McKenna is a renowned ethnopharmacologist and author. Since the 1970s, he has been a leading thinker on and advocate for the study and responsible use of psychedelics. Along with his brother Terence, McKenna co-authored 1975's The Invisble Landscape, perhaps the seminal text on hallucinogenic drugs. A founding board member of the Heffter Research Institute and an advisor and lecturer for numerous other scientific organizations, McKenna has been an authoritative voice on plant hallucinogens for more than four decades. His most recent book The Brotherhood of the Screaming Abyss, a memoir of his journeys with his late brother, was published in 2012. Read More Read Less