 One-self Trinity theories are motivated in part by the concern that if there are three divine selves, this implies that there are three gods. Three-self theories, in various ways, deny this implication. They hold the Persons of the Trinity to be selves (as defined above, section  1.1).  A major motivation here is that the New Testament writings seem to assume that the Father and Son (and, some also argue, the Holy Spirit) are different selves (e.g. Layman 2016, 131–2).