This paper presents a metascientific study called systematology. The frame-of-reference, or the metatheory of systematology is briefly presented. It is then applied in an analysis of Skinner's philosophy and metatheory. Skinner's philosophy is found to be a version of materialistic monism and radical empiricism. Hence, Skinner's meta-theory precludes the application of intervening variables (or hypothetical constructs) of any kind. However, Skinner does use some intervening variables (without surplus meaning), the so-called "response probability'. But in accordance with his radical empiricism he is using the intervening variable very economically, and his theory is found to have the highest degree of testability.