Between words and parts: the philosophy of psychodiagnostics in the mirror of the Internal Family Systems (IFS) model

Abstract

This article offers a philosophical analysis of psychodiagnostics as a communicative practice, with a focus on the Internal Family Systems (IFS) model. The central question revolves around the nature of language in the interaction between practitioners. Drawing upon the philosophical contributions of Ludwig Wittgenstein, Jacques Derrida, Julia Kristeva, Gilles Deleuze, Félix Guattari, and Karl-Otto Apel, as well as contemporary thinkers such as Brian Massumi and Erin Manning, the paper explores language as a medium of meaning-making, symbolic structuring, and discursive normalization. Language is presented not as a neutral tool but as an embodied and affective force that shapes communication, perception, definition, and healing. The analysis contrasts the language of the medical model (with reference to DSM-5) and the dialogical, compassionate vocabulary of IFS, developed by Richard C. Schwartz and further elaborated by Frank Anderson and Martha Sweezy. Using eating disorders as a case study (drawing on the work of Joan Catanzaro), the article examines how diagnostic language frames psychic phenomena, influencing both clinical understanding and therapeutic dynamics. The IFS approach, which conceptualizes the psyche as a multiplicity of “parts” organized around a core Self, fosters internal dialogue, curiosity, and compassionate recognition of each part's protective function. This reorients psychodiagnostics from classification to understanding. As language mediates both diagnosis and intervention, the article argues that psychodiagnostic discourse must be critically re-evaluated in light of contemporary philosophical insights. The IFS model exemplifies an ethical, non-pathologizing, and generative linguistic framework that facilitates psychological healing. In this sense, IFS contributes to the renewal of psychotherapeutic language and to a broader interdisciplinary philosophy of communication grounded in relationality, sensitivity, and mutual recognition