By holding unconventional assumptions, behavior analysts have found themselves confronting traditional philosophical issues, and thus the essays in this part address relations between behavior analysis and other philosophical viewpoints. Day's 1972 founding of the journal Behaviorism (subsequently retitled Behavior and Philosophy) created an arena for engaging behavior analysts in discussion with professional philosophers. But Day had already set a precedent in two important essays.

In his first essay, Day illustrates how daunting such interactions can be by enumerating the many things philosophers know about behaviorism that are not true. Day quickly turns constructive, however, sketching compatibilities between behavior analysis and phenomenology. The radical focus upon verbal behavior and the behavior of the scientist provide his keys. Day asserts that this move permits a surprising tolerance of the varied ways that people speak. Speaking is verbal behavior, to be understood in relation to practices of the community within which it occurs. Descriptions of private events participate in functional relations in precisely the same way that statements of relations between behavior and environment do. A source of tension is the circumspection of behavior analysts regarding vernacular psychological terms that suggest special status for internal processes. Day argues that to make sense of complex aspects of behavior commonly identified with such terms, behavior analysts must put themselves in positions to make relevant observations, in clinical, literary, aesthetic and other similarly complex settings. In noting this approach's affinity to analytic philosophy, and its concern with the pitfalls of ordinary language, this paper leads into Day's next essay, which relates radical behaviorism to Wittgenstein's later work, that of his Philosophical Investigations.

Day initially sketches conventional operationism and logical positivism as adopted by mainstream psychology, along with the usually ignored evidence that they were rejected by Skinner. He credits Verplanck with the observation that Skinner's terminology of responses and stimuli obscured affinities with Tolman and the phenomenologists while suggesting misleading similarities between behavior analysis and the S-R behaviorisms of Hull and Spence. Day finds Skinner and Wittgenstein similarly opposing reductionism and dualism. He also notes parallels between the language games of Wittgenstein and the verbal communities of Skinner, and between Wittgenstein's influential argument against the possibility of private language and Skinner's less widely acknowledged account of the social sources of the language of private events. The two agree that conventional constructions of the problem of reference stand in the way of an adequate account of language, and both finesse the confusions of mentalistic terminology by avoiding the reification of descriptive or predictive terms. Not surprisingly, Wittgenstein and Skinner provoked similar criticisms and answered criticisms in similar ways, by asking about the behavior of the person offering or challenging an explanation or interpretation.

Schnaitter's essay further develops implications of ordinary language by introducing Ryle as complementary to Wittgenstein and Skinner. Ryle's Concept of Mindprovides additional legitimacy and explicit rationale for circumspect use of the vernacular, laying bare awkward assumptions implicit in mentalisms. Ryle showed, for example, that the implied "mental phosphorescence" needed for direct self-monitoring of introspective or cognitive processes is implausible at best. Ryle's dissection of the faulty logic of category errors that permeate conventional explanatory talk provides explicit bases for the more intuitively based discomfort of behavior analysts with such talk.

As described by Schnaitter, Ryle's agenda was to eliminate confusions so as to make discussions in ordinary language more fruitful. In contrast, Lee's review of A New Language for Psychoanalysisdescribes Schafer's advocacy of an outright rejection of whole categories of conventional language. Schafer is even more circumspect than Ryle about interpretive distortions of ordinary phrasing. In reworking the language of his field, he would replace nearly all psychological nouns and adjectives with verbs and adverbs. Lee details how this move can free interpretive prose from "the organocentric myth that has long plagued psychology" by focusing upon actions (verbs) and manners of action (verbs plus adverbs). Regarding psychoanalysis itself, Schafer's proposals would eliminate some characteristics that make that approach uncongenial to behavior analysis, complementing the efforts of behavior analysts such as Kohlenberg & Tsai (1991), who find points in common between psychoanalysis and behavior analysis despite differing agendas and metaphors.

While some aspects of Schafer's work are congenial to behavior analysis, Pepper's World Hypotheses,reviewed by Hayes, Hayes & Reese, develops an overarching framework offering to eliminate fruitless conflict between interpretive positions of whatever kind. Pepper's core thesis is that each position must be evaluated as a whole, for what it does and does not accomplish. His approach systematically justifies positions that many readers already hold intuitively: e.g., recognizing that eclecticism risks confusion, or that it is invalid to base criticism of one viewpoint upon the incompatible assumptions and priorities of another. In addition, Hayes et al. find Pepper's account of special relevance for behavior analysis, to the extent that familiar psychological positions can be identified with Pepper's categories. Similarities and distinctions among those positions often correspond to the compatibilities and incompatibilities of major world views characterized by Pepper. His distinction between contextualism and mechanism as world views makes sense of some longstanding arguments both between behavior analysts and adherents of other viewpoints, and among behavior analysts themselves. Although they do not eliminate the dangers of eclecticism, Hayes et al. suggest how behavior analysis might retain coherence within Pepper's framework while retaining characteristics of more than one world view.

Batts & Crawford's review of Progress and its Problemsand Science and Values,both by Laudan, a philosopher of science, counters Pepper's emphasis on the conceptual independence of alternative viewpoints. To be sure, Laudan, like Pepper, finds that particular empirical claims or facts have differing significance within different viewpoints. Again, the most intractable of interpretive disagreements are likely to occur at the strategic level of aims and objectives, or in the clash between differing world views and their incompatible, often unacknowledged, assumptions. But Laudan finds evidence for substantial influences going in both directions across conceptual levels of facts, methodologies, and systems. Thus, strategic assumptions may change with recognition of facts, while systematic considerations may alter the significance of facts. In Laudan's view, comparative evaluations of data and oppositional criticisms, even across paradigms, can precipitate interpretive change. Batts & Crawford draw on behavior analysis for examples of argument and change that illustrate Laudan's interpretation, including problems of anomalies at empirical and conceptual levels. The clarification of similarities and differences at all levels of analysis that Laudan makes explicit is a thread running implicitly through many essays in this book.