James B. Appel, PhD died March 8, 2024, just a few weeks past his 90th birthday. He was accepted into ACNP membership in 1970 and was a Fellow Emeritus at the time of his passing. Jim enjoyed a long and successful academic career. His formative years as an undergraduate at Columbia College inspired him to study Psychology at Indiana University where he obtained his PhD (1959/60). From Indiana, Jim moved on to the Department of Psychiatry at Yale University where he investigated the relationships between behaviorally active drugs and their neurochemical properties. Within this context, Jim’s research at Yale and subsequently at the University of Chicago focused on the behavioral characteristics of lysergic acid diethylamide (LSD) as well as a range of other drugs with similar characteristics (psilocybin). Jim’s seminal experiments with LSD revealed several important behavioral properties, such as their tendency to produce tolerance and to share stimulus characteristics. From the University of Chicago, he moved on to the University of South Carolina where he spent 30+ years and guided 16 students through to the completion of their doctoral degrees, received a MERIT award from the National Institute on Drug Abuse, and was named Distinguished Professor, much of these honors based on his elegant research revealing the power of well-developed behavioral assays to investigate pharmacological principles. Notably, Jim pioneered drug discrimination assays to preclinically examine the pharmacology of drugs that act in the central nervous system, leading to important insights into the mechanisms of serotonergic medications and psychedelics. He published 111 articles with leading scientists including both behavioral psychologists such as Charles Ferster and psychopharmacologists such as Daniel X. Freedman. As two of the doctoral students mentored by Jim, we celebrate his legacy as a certified genius and a scholar with a unique humorous style unmatched by other peers.