Bessel van der Kolk opens The Body Keeps the Score with his foundational, field-shaping premise: psychological trauma isn't merely stored as narrative memory in the mind, but becomes deeply embedded in the body's physiological systems — nervous system regulation, muscular tension, and hormonal response — meaning genuine trauma treatment requires addressing this bodily dimension directly, not only through verbal, narrative-focused therapy alone.

Van der Kolk's foundational argument:

• Drawing on his extensive clinical and research career studying trauma, he argues that traumatic experience becomes encoded in the body's physiological stress-response systems in ways that persist independent of, and often resistant to, purely verbal or cognitive therapeutic approaches addressing conscious narrative memory alone
• He presents neuroscience research demonstrating measurable, lasting changes in brain structure and function following traumatic experience, particularly affecting areas governing threat detection, emotional regulation, and the capacity to feel safe in one's own body and environment
• This foundational premise directly challenged then-dominant trauma treatment approaches focused primarily on verbal processing and narrative reconstruction, arguing these approaches, while valuable, often prove insufficient without also directly addressing trauma's embedded physiological and bodily dimension

This foundational framing sets up the book's overall project: detailing trauma's specific neurobiological and physiological mechanisms, and examining a range of treatment approaches — including body-based and movement therapies — that directly address this physiological dimension alongside more traditional verbal psychotherapy.