Within the depth-psychology corpus, and most systematically in the sensorimotor tradition developed by Pat Ogden, ‘mobilizing defense’ names the class of sympathetically mediated survival responses — fight, flight, and cry for help — that prepare the organism for active engagement with threat. The term is defined structurally against its counterpart, the immobilizing defense (freeze, feigned death/shutdown), which is parasympathetically governed. Ogden’s work is unambiguous: mobilizing defenses represent the body’s first active line of resistance once the social engagement system has failed to neutralize danger, and their interrupted or incomplete execution at the moment of trauma becomes, in her account, a central somatic substrate of post-traumatic symptomatology. The therapeutic intervention thus becomes, precisely, the careful re-mobilization of these arrested action tendencies — enabling the body to complete, in mindful safety, the defensive movement sequences it could not execute at the time of the traumatic event. A recurring clinical observation across multiple case vignettes is that the impulse to mobilize emerges not from cognitive reappraisal but from somatic awareness itself, lending the construct its distinctive phenomenological weight. The corpus shows no serious dissent from this framework within the sensorimotor domain, though broader psychoanalytic and classical sources do not address the term.