What kind of functions does a theory carry out in the analyst’s mind at work? The author tries to describe, using a few analytic trailers, how Bion Field Theory (BFT) can become an oneiric psychoanalytic tool in the mind of the analyst working with inaccessible states of mind and the violence of nameless turbulences. The hypothesis expressed is that BFT, as described in the works of its principal authors (Ferro, Grotstein, Ogden et.c), seems to evoke a psych-O-analysis that chooses O as psychoanalytic vertex, developing the bionian idea of unconscious as psychoanalytic function of the mind. BFT introduces explains and illustrates an oneiric model of the mind and of the analytic cure. The priority given by this theory to the contact with emotional experience and the capacity to stay at one ment with the unknown emotional experience circulating in the hic et nunc, seems, in author’s analytical experience, to promote both the development of an authentic analytic Self and analytic ethic and a process of subjectivation in analyst, patient, analytic experience.