Verbal BehaviorB.F. Skinner in which the author presents his ideas on language. For Skinner, speech, along with other forms of communication, was simply a behavior. Skinner argued that each act of speech is an inevitable consequence of the speaker's current environment and his behavioral and sensory history, and derided mentalistic terms such as "idea", "plan" and "concept" as unscientific and of no use in the study of behavior. For Skinner, the proper object of study is behavior itself, analysed without reference to mental structure, but rather with reference to the structure and history of the environment in which particular behaviors occur.
Verbal Behavior touches on many perennial issues in philosophy, most notably the issue of rationalism vs. empiricism. For rationalists, the structure of human knowledge comes from within and is largely innate: we may learn from experience, but the essence of human thought is the ability to reason — to aquire new knowledge through deduction and induction, and to reduce the clamour of information that reaches us through our senses to pure mathematical concepts such as "square" and "melody". In its extreme form, as espoused by Descartes, rationalism holds that virtually all knowledge may be arrived at by "pure reason", i.e. by logical reasoning from a set of self-evident first principles. From this perspective, the role of the senses in the formation of knowledge is merely that of a catalyst, accelerating a process which is internal to the mind/brain. In contrast, Skinner was an extreme empiricist, arguing that notions such as "reason", "idea", "knowledge" and "concept" have no scientific significance. For example, a speaker of English could not, according to Skinner, be said to have a "knowledge of English" in any well-defined sense — he would merely have aquired a set of behaviors which allowed him to respond appropriately during English conversations.
The book itself has been no less controversial than these broader philosophical issues, and is probably now more famous for the controversy surrounding it than for its actual contents. Particularly famous is Noam Chomsky's scathing review , which is said by many to have initiated a "cognitive revolution" in Psychology, a shift from the study of behaviour for its own sake to a study of the mental mechanisms which underly it. Empiricist ideas about behavior are still being explored, especially in the field of cognitive science known as connectionism.