(Final version accepted 11 September 2008)

The kind of science that psychoanalysis is (can be), and the kind of research appropriate to it, qualitative and/or quantitative, have been divisive issues from the very inception of the discipline. I explore in detail the complexity of these issues, definitional and semantic, as well as methodological and substantive. A plea is made for the application of qualitative (idiographic) and quantitative (nomothetic) research methods, each to the extent that is appropriate, separately or in conjunction, across the entire spectrum of research domains in psychoanalysis, empirical, clinical, conceptual, historical, and interdisciplinary.