Due to his inquisitive mind and interest in science, by age eight Heard began to turn toward skepticism, regarding the conventional Christianity of his forebears—a process that was completed by the time he was sixteen.

[4] In the 1920s and early 1930s, he acted as the personal secretary of Sir Horace Plunkett, founder of the cooperative movement, who spent his last years at Weybridge, Surrey.

Naomi Mitchison, who admired Plunkett and was a friend of Heard, wrote of that time: "H.P., as we all called him, was getting past his prime and often ill but struggling to go on with the work to which he was devoted.

Like that of his friend Aldous Huxley (another in the circle), the essence of Heard's mature outlook was that a human being can effectively pursue intentional evolution of consciousness.

[9] Heard concluded that the impediment to be addressed was "the problem of letting in a free flow of comprehension beyond the everyday threshold of experience while keeping the mind clear.

Professionally, Greene ultimately pursued a career in journalism and film-making, but at the founding of Trabuco, he had exercised some talent in the planning of architecture and land-development.

[11] In the mid-1950s, Heard was featured as series lecturer in the Sequoia Seminars (a precursor to the Esalen Institute), organized by Emilia and Harold Rathbun, PhD.

In August 1956, Alcoholics Anonymous founder Bill Wilson first took LSD—under Heard's guidance and with the officiating presence of Sidney Cohen, a psychiatrist then with the California Veterans Administration Hospital.

[citation needed] In the late 1950s, Heard also worked with psychiatrist Cohen to introduce others to LSD, including John Huston and Steve Allen.

Religion writer Don Lattin wrote that Heard's view was "LSD might provide an experience of the great mysteries, but it offered no instant answers.

"[15] In modern industrial societies, a person, especially if educated, has the opportunity to begin entering the "first maturity" of the humanic "total individual" in his or her mid teens.

According to Heard, the second maturity can be one that lies beyond "personal success, economic mastery, and the psychophysical capacity to enjoy life" [15]240 Heard termed this phase "Leptoid Man" (from the Greek word lepsis: "to leap") because humans increasingly face the opportunity to "take a leap" into a considerably expanded consciousness, in which the various aspects of the psyche will be integrated, without any aspects being repressed or seeming foreign.

A society that recognises this stage of development will honour and support individuals in a "second maturity" who wish to resolve their inner conflicts and dissolve their inner blockages and become the sages of the modern world.

As Heard put it metaphorically, "you notice there aren't these separations... we're parts of a single continent, it meets underneath the water.” Further, instead of simply enjoying biological and psychological health, as Freud and other important psychiatric or psychological philosophers of the "total-individual" phase conceived, Leptoid man will not only have entered a meaningful "second maturity" recognised by his or her society, but can then become a human of developed spirituality, similar to the mystics of the past; and a person of wisdom.

[citation needed] Heard died on 14 August 1971 at his home in Santa Monica, California, of the effects of several earlier strokes he had, beginning in 1966.

[17] Heard's general philosophy and the ideas and opinions of his later years, were influences on Myron Stolaroff, the electrical engineer who in 1961 founded the Institute for Advanced study, in Menlo Park, California.

Michael Murphy and Dick Price started organizing seminars at Esalen near Big Sur in 1962, with Heard being a notable presenter.

Three other characters—Cary Grant, Aldous Huxley and Claire Boothe Luce—are modeled on those widely known public figures, each of whom, in real life, actually had repeated LSD experience.

[21] Mr. Mycroft and his friend, Mr. Silchester, appeared in three novels: A Taste for Honey, 1941 (televised in 1955 as Sting of Death and filmed, as The Deadly Bees, 1967); Reply Paid; and The Notched Hairpin.