The author traces the research path of René Kaës, starting from the early studies of the 1970s. Focusing in particular on the concepts of the unconscious alliance, link and subject of the link, and intersubjectivity, the author analyzes the metapsychological reformulations pro-posed by Kaës and that led him to the idea of a third topology and of a third type metapsychol-ogy.
Keywords: Unconscious, intersubjectivity, unconscious alliances, third topic.