Throughout the narrative of Many Lives, Many Masters, Weiss describes a personal journey from skeptical scientist to enthusiastic practitioner of past life regression and believer in reincarnation. In addition to delineating his own journey, Weiss anticipates the skepticism of his audience and takes pains to demonstrate the authenticity of his psychic experiences with Catherine in order to take the audience on its own journey from skeptic to believer by the end of the book.

Weiss concluded his academic studies and began his career in psychiatry as a scientist driven by logic and reason. Following his residency at Yale, Weiss “joined the new breed of biological psychiatrists […] merging the traditional psychiatric theories and techniques with the new science of brain chemistry” (38). He described himself at this time as “obsessive” and “inflexible” (38) which he considered useful traits for a doctor. When first confronted with the incredible past life information Catherine revealed to him under trance, Weiss’s reaction was to be “skeptical about life after death, reincarnation, out-of-body experiences, and related phenomena” (30) because logic was against such stories.

Weiss felt that he needed more facts to validate his experiences in session with Catherine.