Education for the practice of psychology has evolved through a preprofessional phase, a scientist-professional phase, and a professional phase, in which each successive pattern of education complements but does not replace the prior pattern. Each phase of development is grounded in its own assumptions about relations between research and practice. The concepts of practice as applied science, reciprocity of science and profession, and practice as disciplined inquiry are considered. The concept of practice as disciplined inquiry is appropriate to the education of professional psychologists. Complementarity of basic research, applied research, and professional service requires appreciation of fundamental differences as well as similarities in the structure of research and practice. Among all the misunderstandings that contaminate rational discussion about the education of professional psychologists, none is more fundamental nor more difficult to dislodge than the idea that the direct education of professionals entails a rejection of research. No one I respect has ever suggested that. I never have. My central claim is that scientific research and professional service are different in important ways, and that different forms of education are required to prepare people for careers of research, in the one case, or careers of professional service, in the other case. Combinations are possible, but rarely fit the dispositions of students or the demands of employment following graduate education. Because I have been writing and speaking on this topic for more than 25 years and still'hear otherwise sane and literate people ask me why I am opposed to science, I hold no illusion that my remarks will put the confusion to its final rest. All I intend in the following statement is to approach the issue of relations between research and practice from a somewhat different direction than I have taken before and hope that my comments will be constructive. First I will offer a brief review of the history of education for the practice of psychology, within which three clear phases can be marked. Then I will examine assumptions about relations between the science and the profession that have predominated in each phase, and conclude with the recommendation that basic scientists, applied researchers, and professional psychologists pursue their distinct but related missions in complementary and cooperative ways.