Influenced by pragmatism and pepperian contextualism, some behavior analysts have denied any ontological assumption concerning substance to radical behaviorism. As a result, a radical version of relationism is defended in which the only property relevant to the existence of behavior is the very relation that defines it. The aim of this paper is to evaluate the pertinence of that position. Three questions will guide our analysis: (1) Why is substance not important to radical behaviorism?; (2) Why is substance important to radical behaviorism?, and (3) What is, in fact, the ontological attitude more consistent with radical behaviorism? It is argued that extreme relationism does not accurately reflect radical behavioristic ontology and it is suggested that substantial relationism is a more coherent position.
Radical behaviorism; Skinner; Behavior; Ontology; Relationism; Substance