This letter begins by positioning psychology as the philosophical study of the “fountain of ever‑flowing good” within man—the soul. Ancient psychology, he explains, was rooted in metaphysics and regarded the soul as the medium between spirit and body. This tradition flourished in India, Egypt, Greece, and later among Christian mystics and Rosicrucians such as Paracelsus, Jacob Boehme, and Robert Fludd. The ancients viewed the universe as a triune structure—spirit, soul, and body—and saw the soul as a vast, reflective organism binding the individual to celestial forces. It was the source of consciousness, temperament, imagination, and memory, and evolution was understood as the soul growing through bodies rather than bodies developing independently. The aim of ancient psychology was to clarify the soul’s constitution and cultivate its dominion over the body through philosophical discipline.

Hall then contrasts this with modern psychology, which shifted from metaphysical breadth to scientific specialization. Modern psychology limits itself to analyzing mental processes and divides the mind into conscious, subconscious, and unconscious spheres. He outlines how subconscious complexes distort thought, how repression shapes introversion, and how psychoanalysis attempts to infer the nature of consciousness from its effects—“modern cabalism,” as he calls it. Psychotherapy, in turn, seeks to correct mental disorders to prevent physical consequences, since wrong thinking perpetuates illness. Hall concludes that while modern psychology has practical value, it lacks the philosophical depth of the ancient system. True psychological health requires restoring balance between body, mind, and soul—freeing the intellect from biases and allowing the soul to regain clarity and authority.