Louis Sander's bold and ambitious theoretical synthesis deserves careful attention from psychoanalysts of all persuasions. Sander's cutting-edge approach draws on infant observation research, nonlinear dynamic systems theories, and current biology, physics, and other “hard” sciences. He is rethinking the psychoanalytic approach to psychic structure, motivation, and therapeutic action. In so doing, he updates Freud's project of linking psychoanalysis with scientific paradigms, but without reductionism, epistemological naivete, or an implicit antipsychological attitude.

Sander emphasizes the dynamic relationships between elements in systems. His method draws parallels between the different levels of the functioning of natural systems, starting with the basic “biological” level of cells and organs and moving toward the psychic and interpersonal phenomena that are of greatest interest to psychoanalysts. In this way, he opens a window for a broad and inclusive “relational metapsychology.”