Ettinger's work follows the Freudian and Lacaniantraditions of psychoanalysis and challenges their phallocentric conceptualizations. Her book also examines Emmanuel Levinas, "Object-relations" theory and Gilles Deleuze/Félix Guattari and also critiques them, reformulating subject and feminine difference. Ettinger's book is considered the initiator of the Matrixial Trans-subjectivity theory, or simply "The Matrixial". The book influenced discussions of subjectivity as encounter, the matrixial gaze, matrixial time, matrixial space, co-poiesis, borderlinking, borderspacing, co-emergence in differentiating and differentiating, transconnectivity, matrixial com-passion, primary compassion, compassionate hospitality, witnessing, co-fading, severality, matrixial transformational potentiality, archaic m/Other, fascinance, encounter-event, besideness, primal Mother-phantasies of Not-enoughness, devouring and abandonment, empathy within compassion, empathy without compassion, seduction into life, and metramorphosis. ScholarGriselda Pollock writes, "The matrixial gaze emerges by a simultaneous reversal of with-in and with-out, by a transgression of borderlinks manifested in the contact with-in/-out and art work by a transcendence of the subject–object interval which is not a fusion, since it is based on a-priori shareability in difference." Scholar Lone Bertelsen has analyzed the claims Ettinger's work makes on behalf of the "feminine", especially the "existential ethic in the feminine". Pat Paxson writes that it approximates the Lacanian gaze, "but from a different angle", adding that it is "pushed by a desire for linking and relationships". Ettinger continued to explore this concept in her published work, including her 2006 book, The Matrixial Borderspace.
The matrixial gaze uses the matrix to counter Lacan's phallic gaze. Similar to Lacan's formulation, which is a metaphorical reference to anatomy to discuss symbolic masculine power, the matrix is a metaphorical reference to the uterus in order to discuss relationality. This shift was "not just to exchange an organ and its image for another, but to conceive of an alternative to the phallus in terms of structure, mechanism, functions, logic". According to Pollock, the matrix allows us to escape the "notion of the discrete and singular subject formed by the establishment of the boundaries that distinguish it from an oceanic or undifferentiated otherness of the world or the maternal body". Pollock notes that thinking in terms of the phallus and castration anxiety casts subjects in terms of "separations, splits, cuts, and cleavages". Venn adds that the matrix allows the concept of the gaze to extend beyond the visual realm to touch, sound, and movement.
