Early researchers like Stanislav Grof almost certainly didn't have expanding consciousness on their list of possible medical benefits. Nor could they have imagined that a respected Harvard doctor by the name of Timothy Leary would be so moved by the possible uses of lysergic acid diethylamide, as it's known to pharmacologists, that he would feel compelled to walk away from this prestigious post in order to found a countercultural movement.

Yet the fans of LSD across the Atlantic (many of whom are no longer with us; expanding consciousness has always been a hazardous endeavor) quickly elevated it beyond uses in treating patients with psychiatric maladies to mythic status.

The colorful little tab, as we all know now, was fated to become a kind of icon for the hippie movement, the ethic of questioning authority and the tectonic social changes of the late '60s.

Grof, who emigrated to the United States around that time, proved himself one of the great survivors of the era and remains a respected authority not just on the drug he pioneered but on human psychology in general.

His reputation as a psychiatrist is built on over 40 years' experience in research of what are called "nonordinary states of consciousness," or those induced by psychedelics and nondrug techniques, such as his own holotropic breathwork system.

He's also called one of the founders and chief theoreticians of transpersonal psychology.

Along with his patients and colleagues, Grof has conducted a phenomenally thorough survey of the human mind. His team's observations are so unique because of the wide range of subjects and because they systematically map regions that no one else had ever explored.

His 1975 book, Realms of the Human Unconscious, describes a four-level "mindcollage," a conclusion Grof reached after studying some 4,000 LSD therapy sessions with subjects who ranged from psychotics and neurotics to healthy volunteers.

Though places like the Esalen Institute in Big Sur, California, are these days thought of as one of the sillier feel-good excesses of the '70s, there can be little argument that Grof's long residency there had a dramatic impact on thousands of lives.

The Western world as we know it would have been a much different place had this curious clinician not made it out of Czechoslovakia, where the state controlled every aspect of psychological research, sometimes co-opting it to meet its own paranoid Cold War needs (LSD as a chemical weapon? One wonders how much the Defense Ministry mugwumps were taking — though, to be fair, the question should also be asked of the CIA).

As for whether medical professionals should be allowed to resume legal testing and research of LSD on humans, as some advocates argue, those who know the drug best seem doubtful. While there are legions who say they experienced life-changing revelations with the help of LSD therapy, others say it has scarred many lives and its effects are just too unpredictable.