petition in 1984. transpersonal psychology has been criticized for lacking conceptual, evidentiary, and scientific rigor. in a review of criticisms of the field, cunningham writes, "philosophers have criticized transpersonal psychology because its metaphysics is naive and epistemology is undeveloped. multiplicity of definitions and lack of operationalization of many of its concepts has led to a conceptual confusion about the nature of transpersonal psychology itself (i.e., the concept is used differently by different theorists and means different things to different people). biologists have criticized transpersonal psychology for its lack of attention to biological foundations of behavior and experience. physicists have criticized transpersonal psychology for inappropriately accommodating physic concepts as explanations of consciousness." albert ellis, a cognitive psychologist and humanist, has questioned the results of transpersonal psychotherapy. in 1989 he cooperated with raymond yeager for the release of why some therapies don't work: the dangers of transpersonal psychology, where the authors compared the results of transpersonal psychology with the effects of rational-emotive therapy, noting the dangers of the transpersonal approach. ellis has also questioned the scientific status of transpersonal psychology, and its relationship to religion, mysticism and authoritarian belief systems.