 Analyzed by Melanie Klein, he himself became an analyst in 1945 and continued to work within the Kleinian movement, alongside such figures as Wilfred Bion and Hanna Segal.Among his most significant contributions were his groundbreaking exploration of projective identification; the development of the concept of "confusion"; and the foundation of a theory of destructive narcissism, since taken up and developed by André Green and Otto Kernberg.Rosenfeld saw confusion as a half-way house between splitting and reintegration, either as a progressive step towards the latter, or as a regression from it.