In this essay we introduce the idea of an epistemic triangle, with factual, theoretical, and conceptual investigations at its vertices, and argue that whereas scientific progress requires a balance among the three types of investigations, psychology's epistemic triangle is stretched disproportionately in the direction of factual investigations. Expressed by a variety of different problems, this unbalance may be created by a main operative theme—the obsession of psychology with a narrow and mechanical view of the scientific method and a misguided aversion (...) to conceptual inquiries. Hence, to redress psychology's epistemic triangle, a broader and more realistic conception of method is needed and, in particular, conceptual investigations must be promoted. Using examples from different research domains, we describe the nature of conceptual investigations, relate them to theoretical investigations, and illustrate their purposes, forms, and limitations. (shrink)