In 1945, Skinner published an influential piece on the operational analysis of terms in which he attacked the prevailing philosophy of science that he called methodological behaviorism. This is the view that there is a distinction between public and private events and that psychology (to remain scientific) can deal only with public events. According to this view, private events are "mental" and, therefore, beyond our reach. This is the "arid philosophy of truth by agreement"(Skinner, 1945): something is meaningful or scientific (objective) only if at least two observers agree on its existence. Thus, private experience is excluded because it is subjective (by definition) and we can deal only with that which is objective. Methodological behaviorism and almost all cognitive theories leave the mind to philosophers.
It is almost invariably assumed that Skinner held the views of the methodological behaviorists and would not let us study the mind because it is unscientific (Anderson, 1990). That is absolutely false. Indeed, Skinner presented his own position, radical behaviorism, in contrast to methodological behaviorism! Radical behaviorism is Watsonian in that it does not distinguish between private and public events. In so doing, it omits nothing commonly thought of as mental, but it treats "seeing" as an activity similar in kind to walking (cf., Malone, 1990).
Skinner did not deny the existence or the importance of personal experience any more than did Watson, but he did deny the mind/body dualism of the mentalists and the methodological behaviorists. Thinking is something that we do, just as is walking, and we do not think mental thoughts any more than we walk mental steps.