A three-way conversation, or trialogue, recorded at Esalen in 1989.

What could have been the cause for the breakthrough in the evolution of human consciousness around 50,000 years ago? Collective memories of predation and how they may shape our minds today. The role of the imagination in our evolution. Physiological evolution and the idea of divine brain surgery. The psilocybin hypothesis. The transformation of human nature through connection with higher levels of consciousness in the universe. The universal information field and cosmic evolution. 

This Trialogue and others are available in book form:
https://www.sheldrake.org/books-by-rupert-sheldrake/the-evolutionary-mind

Terence McKenna was an ethnopharmacologist, shamanologist, and author, known for his theories on plant hallucinogens and the novelty wave, and the bardic skill with which he conveyed his ideas. Sadly Terence died aged 53 on April 3, 2000.

Ralph Abraham, PhD, is a Professor of Mathematics at the University of California, Santa Cruz, author, and pioneer in the fields of Chaos theory, computer graphics, visual mathematics and dynamical systems.