One of the issues plaguing contemporary theoretical psychology concerns the question whether our discipline should proceed on a pluralistic or monistic epistemic base. Two historical analyses of a crisis in psychology, those of Bühler and Vygotsky, are discussed because they seem to apply as prototypes to this strategic alternative. A comparative review shows that this common suggestion is untenable. Both views, albeit differing in other respects, share the goal of a non-eclectic unification of psychology in non-empiricist terms. The relevance of Vygotsky's "General" and Bühler's "Axiomatic Psychology" to modern attempts at a conceptual and methodological refoundation of psychology is considered.