Terence McKenna was an ethnopharmacologist, shamanologist, and author, known for his theories on plant hallucinogens and the bardic skill with which he conveyed his ideas. Sadly Terence died aged 53 on April 3, 2000. We were close friends and had many wonderful conversations, many of which are available on my website at: 
https://www.sheldrake.org/videos/terence-mckenna

Two of our conversations, trialogues with Ralph Abraham,  were published in book form:

Chaos, Creativity and Cosmic Consciousness
https://www.sheldrake.org/books-by-rupert-sheldrake/chaos-creativity-and-cosmic-consciousness

The Evolutionary Mind: Conversations on Science, Imagination & Spirit 
https://www.sheldrake.org/books-by-rupert-sheldrake/the-evolutionary-mind

This is an excerpt from a conversation with Roi Yozevitch
https://www.youtube.com/c/RoiYozevitch