The unification scheme proposed by Henriques in his article “Psychology Defined” (this issue) holds promise as a coherent and comprehensive approach to psychology and as a helpful way to think about the relation of psychology to other sciences. There is, nevertheless, room for concern that there is no concept of unification to date that does not neglect important dimensions of human experience. It is argued that the disunities in psychology need not result in a sense of disciplinary inferiority. In fact, many leading scholars now challenge the belief that other sciences are models of integration and unity. It is also argued that there are not true type identities between levels of organization (e.g., experience and underlying neurological processes). Accordingly, there are serious questions about the kind of unity that can be achieved. © 2004 Wiley Periodicals, Inc. J Clin Psychol.