The history of parts work — a century of listening to the inner world

Pierre Janet and the divided self (1880s–1910s)

Pierre Janet was a French neurologist and psychologist working in Paris at the end of the nineteenth century, and he was observing things that Freud had not yet named. His patients showed what we would now call dissociation — fragments of experience that seemed to operate independently of conscious awareness. He called these "fixed ideas" and described how traumatic experiences could split off from ordinary memory, continuing to influence behaviour from below the surface.

Janet was the first clinician to document systematically that the mind responds to overwhelm by compartmentalising — not as a disorder, but as an intelligent adaptive response. His work fell somewhat into obscurity as Freud's model took centre stage, but modern trauma therapists — including Bessel van der Kolk — have returned to Janet as a foundational figure.

Carl Jung and the inner cast of characters (1910s–1960s)

Carl Jung developed a psychology of the psyche as populated — not by a single ego, but by archetypes, complexes, and the famous Shadow: the parts of the self we cannot see directly and tend to project outward. Jung was the first major Western psychologist to insist that psychological healing involves integration — bringing the hidden parts into relationship with the whole — rather than defeating or eliminating the difficult aspects of the self.

His active imagination technique, in which clients would enter into dialogue with dream figures or inner images, is a direct ancestor of parts work practices today.

Eric Berne and Transactional Analysis (1950s–1970s)

Eric Berne developed Transactional Analysis, which gave the general public a simple but revolutionary map: every person operates from three ego states — Parent, Adult, and Child — each with distinct feelings, beliefs, and behaviours. TA was the first model to enter mainstream culture with the idea that internal conflict reflects the relationship between these inner states. It made the multi-self idea accessible, pop-cultural, and clinically useful.

Hal and Sidra Stone and Voice Dialogue (1970s–1980s)

Hal and Sidra Stone, American psychologists, developed Voice Dialogue in the 1970s — a practice that takes the inner sub-personality model a radical step further. Rather than talking about inner parts from a distance, clients in Voice Dialogue speak as those parts, with the therapist facilitating direct dialogue between different aspects of the self.

This was transformative: it moved the locus of change from understanding to relationship. You don't have to comprehend a part to heal it. You have to meet it. Voice Dialogue directly influenced an entire generation of therapists, including Richard Schwartz.

Richard Schwartz and the birth of IFS (1988–present)

Richard Schwartz was a family systems therapist in Chicago who, in the mid-1980s, began to notice something his clinical training hadn't prepared him for. His clients kept describing their experience in terms of parts — a part of me wants this, but another part is terrified — and when he followed that language rather than redirecting it, something extraordinary happened. The parts appeared consistent. They had their own ages, their own beliefs, their own histories. And underneath all of them was something stable, wise, and compassionate that Schwartz eventually called Self.

He developed the Internal Family Systems model over the following decade, publishing his first major work in 1995. IFS has since been studied in clinical trials, added to SAMHSA's National Registry of Evidence-Based Programs and Practices, and generated a global community of practitioners and self-taught students who describe it as having changed the way they understand themselves.

Where parts work is now

Today, parts work appears across multiple modalities — IFS, EMDR (which incorporates parts concepts in later phases), somatic experiencing, DBT (dialectical behavioural therapy's skills address internal states), and schema therapy all incorporate the understanding that people are internally multiple and that healing involves the relationship between inner states.

The field is growing. And the core insight — that the parts of you that cause the most trouble are also the parts that have worked the hardest to protect you — is becoming part of the mainstream cultural understanding of what it means to be a person.

If the vocabulary used in this lineage is new, the IFS glossary is a clear plain-English reference. If you want to begin your own practice, the parts work exercises are a gentle starting place.