Behaviorism is a twentieth-century term, made popular by the psychologist John Watson (1878–1958) in 1913. Although Watson introduced psychological behaviorism, there is also a version called philosophical behaviorism.
Psychological behaviorism is the view that psychology should study the behavior of individual organisms. Psychology should be defined not as the study of the mind and internal mental processes via introspection, but as the Page 275 | Top of Articlescience of behavior. The most famous proponents of psychological behaviorism were John Watson and B. F. Skinner (1904–1990). Other notable behaviorists were Edwin Guthrie (1886–1959), Edward Tolman (1886–1959), Clark Hull (1884–1952), and Kenneth Spence (1907–1967).
Philosophical behaviorism, by contrast, is a research program advanced primarily by philosophers of the twentieth century. This school is much more difficult to characterize, but in general, it is concerned with the philosophy of mind, the meaning of mentalistic terms, how we learn this meaning, and how we know when to use these terms. Important philosophical behaviorists include Bertrand Russell (1872–1970), Gilbert Ryle (1900–1976), Ludwig Wittgenstein (1889–1951), Rudolf Carnap (1891–1970), Otto Neurath (1882–1945), Carl Hempel (1905–1997), and W. V. O. Quine (1908–2000). Other philosophers such as Daniel Dennett (b. 1942), Wilfrid Sellars (1912–1989), Donald Davidson (1917–2003), and Richard Rorty (b. 1931) have behavioristic sympathies to varying degrees.
Besides these two generic versions of behaviorism, there are several subvarieties (see Kitchener 1999; Zuriff 1985). Eliminative behaviorism is the denial that there are any mental states at all; there is just behavior. Methodological behaviorism is the view that it does not matter whether there is a mind or not; psychologists should just study behavior. Logical behaviorism (also called analytic behaviorism or semantic behaviorism) is the view that all mentalistic terms or concepts can be defined or translated into behavioral terms or concepts. Epistemological behaviorism and evidential behaviorism hold roughly the view that the only way to know about a mental state is by observing behavior.
A BRIEF HISTORICAL OVERVIEW
It should be noted that in the intellectual history of western culture there have been individuals who held views very similar to theories supported by one or both of these movements, even though they did not use the term behaviorism; others have championed views that may not be characterized as “behavioristic,” but which have had a strong impact on behavioristic ways of thinking (see Peters 1973–1974; Harrell and Harrison 1938). The writings of Aristotle (384 BCE-322 BCE), in particular his De Anima, his account of practical rationality in the Nicomachean Ethics, and his scientific work on animals (De Motu Animal), contain ideas that were assimilated by later behaviorists. Likewise, the writings of the Stoics and the Skeptics contain several theoretical accounts that are sympathetic to a general behavioristic approach, especially their views about animal cognition.
Several seventeenth- and eighteenth-century works inspired behavioristic followers, including Thomas Hobbes’s generally mechanistic account of the mind, The Leviathan (1651), René Descartes’s 1637 account of animal behavior, Discourse on Method, and the writings of several individuals who belonged to the French Encyclopedists tradition of the Enlightenment, such as Julien de La Mettrie’s Man a Machine (1748), Pierre Cabanis’s On the Relations between the Physical and the Moral Aspects of Man (1802), and Baron d’Holbach’s The System of Nature (1770), among others.
The Cartesian Tradition A major philosophical issue emerging in the seventeenth and eighteenth centuries concerned the question of the nature of the human mind and the animal mind: Is it possible to provide a mechanistic, materialistic, and deterministic account of the human mind, or must one appeal to principles that are quite different from those used in modern physics? Descartes argued that the human mind is made of a substance different from any found in the natural world, one that operates by principles at odds with the ordinary causal processes of inorganic matter. Although humans possess this special kind of spiritual being, animals do not; they are, quite simply, machines that operate by ordinary “matter in motion” (Descartes 1637). Humans are radically different from such animals because the human mind is made of a quite different substance that is not observable by ordinary naturalistic methods; however, humans have a kind of special access to their own minds, found by means of internal reflection or introspection. None of this was true of animals, all of whose behavior can be explained mechanistically in terms of simple mechanical principles (see Rosenfeld 1941).
The question that arose, therefore, was this: If Descartes was correct about his animal psychology, was he also correct about human psychology? Do we need to appeal to a special nonmaterial substance to explain the behavior of humans, or can all of their behavior be explained in the same ways we explain animal behavior? Although Descartes’s answer was widely accepted, there were a few individuals who argued that humans are no different from animals, and hence if animal behavior can be explained along naturalistic lines—by observing their behavior and trying to explain it by deterministic laws of matter in motion—the same is true of humans. This was the view of some eighteenth-century thinkers who championed a purely naturalistic, materialistic, deterministic, and mechanistic account of humans. They were the forefathers of mainstream psychological behaviorism.
The nineteenth century produced philosophers and scientists who, in one form or another, contributed ideas that were fuel for the behaviorists’ fire. An example are the Page 276 | Top of Articlepost-Kantian German idealistic philosophers, many of whom stressed the importance of praxis, or human action. These ideas in turn strongly influenced members of the philosophical/psychological school of pragmatism, including Charles Sanders Peirce (1839–1914), William James (1842–1910), and John Dewey (1859–1952). These pragmatists were concerned with understanding and providing an account of humans and animals that focused on their action—something that organisms did, something they tried to accomplish as they interacted in their physical and social environment. Strongly influenced by the Darwinian revolution, the pragmatists employed a Darwinian model of organisms adapting to their environments to understand action. Such an approach at once stressed the problem-solving nature of human and animal mentality and the assumption that everything that exists must be understood in a “functional” way—that is, how entities such as ideas are useful in an organism’s struggle to survive in its environment. All intelligence was to be explained in this way, as an “instrument of action.”
Although Sigmund Freud was no behaviorist, he did aid the behaviorist cause by challenging the reigning Cartesian model of the mind that maintained that humans had an immediate and privileged access to the inner workings of their minds that employed a first-person rather than a third-person perspective on the mind, and that tended to draw a sharp distinction between the human mind and the animal mind. Freud argued that the mind is not transparent to our internal gaze because most of our mental activity is going on below the surface at the level of the unconscious (Freud 1900). If this is correct, then the method of psychology cannot be assumed to be introspective. This opened the way to alternative methods of psychological investigation.
The work of Ivan Pavlov on the conditioned reflexes of dogs ( 1960), as well as the work of other Russian physiological scientists, provided behaviorists with scientific accounts of behavior. Behavior occurs, persists, and changes as a result of classical conditioning: An original stimulus elicits some response; another stimulus is subsequently paired with the original stimulus, thereby acquiring the power to elicit the response. This version of S-R psychology is the paradigm for at least early behaviorism, providing an explanation of behavior. The other kind of learning employed by behaviorists was instrumental conditioning (operant conditioning, trial and error learning), first introduced in 1898 by Edward Thorndike (1874–1949). In instrumental conditioning, a response is learned because it is reinforced by a stimulus—the reward—where the response is instrumental in obtaining the reward. Classical and instrumental learning promised to explain all of behavior. None of this seemed to require private internal workings of a special kind of substance. Psychology could take its place among the objective natural sciences.
In psychology, behaviorism began with John Watson, who coined the term behaviorism and set forth its initial premises in his seminal article “Psychology as the Behaviorist Views It” (1913). Behaviorism, Watson suggested, should be considered an objective, natural science, one that studies the public, observable behavior of organisms. Rejecting the method of introspection practiced by his predecessors, Watson suggested a different method to be used by psychologists: Study the observable behavior of others, and to explain it, given the stimulus, predict the response; given the response, predict the stimulus. The aim of psychology, therefore, was the prediction and control of behavior. What then of the mind, that special substance that Descartes claimed was the special province of humans? Watson gave several different answers over the course of his career, including eliminative behaviorism, methodological behaviorism, and, later, the view that the mind exists but is the same as behavior. In short, Watson’s argument was this: Humans and animals are not radically different from each other, and since the behavior of animals can be explained without appealing to consciousness, the behavior of humans can be explained without appealing to consciousness, too. With the rise of the cognitive sciences in the 1960s, this conclusion was denied, and so was the claim that the behavior of animals can be explained without appealing to consciousness.
The key question is, what did Watson mean by “behavior”? Was it a mechanical physical movement of the body or something more complex—the intentional, purposive action of a rational agent? If the latter, then how can a purely mechanistic science account for it? This perplexing question remained at the center of discussion for decades. Doubts about a mechanistic approach gave impetus to versions of purposive behaviorism found in the writings of William McDougall (1912), Edwin Holt (1915), and E. C. Tolman (1932). Indeed, McDougall and Holt had been proposing a kind of teleological behaviorism before Watson had appeared on the scene.
We can divide the history of psychological behaviorism into several periods: (1) classical behaviorism, (2) neobehaviorism, (3) operant behaviorism, and (4) contemporary behaviorism. The first period (1912–1930) introduced the theory of behaviorism championed by John Watson and several other early advocates of behaviorism, including Max Meyer, Albert Weiss, Walter Hunter, and Karl Lashley. These behavioristic accounts were, by and large, naive, sketchy, and inadequate, but they set forth the general program of psychological behaviorism.
The second period (1930–1950) was the era of neobehaviorism, so called because its philosophical underpinnings were somewhat different from its predecessors. Neobehaviorism was wedded to classical learning theory (see Koch 1959), and neobehaviorists were concerned with what form an adequate theory of learning should take. The main figures were Edwin Guthrie, Edward Tolman, Clark Hull, B. F. Skinner, and Kenneth Spence. All of these individuals spent a great deal of time laying out the philosophical bases of their respective kinds of behaviorism, and in doing so, they borrowed heavily from the school of logical positivism, which was influential at the time (but see Smith 1986). This resulted in an emphasis on the importance of operational definitions, a preference for a hypothetico-deductive model of theory construction, and a focus on issues about intervening variables versus hypothetical constructs, and the admissibility of neurological speculation. This move toward postulating internal mediating responses continued with later Hullian neobehaviorists such as Charles Osgood, Neal Miller, O. H. Mowrer, Frank Logan, and others.
The last two phases of behaviorism are more difficult to characterize. Skinner’s version of behaviorism—operant behaviorism—is markedly different from most of the other neobehaviorists, and yet he is perhaps the best-known behaviorist. Indeed, after the demise of Hullian learning theory in the 1960s, the main thrust of the movement switched to Skinner’s distinctive version of behaviorism.
Denying he was an S-R psychologist, Skinner championed an operant account of learning, in which a response that occurs is reinforced and its frequency is increased (1938). The response—for example, a bar press or a key peck—is not elicited by any known stimulus, but once it has occurred, its rate of response can be changed by various kinds of reinforcement schedules. The response can also be brought under experimental control when it occurs in the presence of a discriminative stimulus (e.g., light). Such a relationship—discriminative stimulus, response, reinforcement—is sometimes called a contingency of reinforcement, and it holds a central place in Skinner’s brand of behaviorism. Skinner himself characterized his behaviorism as a “radical behaviorism” because rather than ignoring what is going on inside the organism, it insists that such events are still behavior (1974). However, such behavior still is caused by environmental variables.
Skinnerian behaviorism was the dominant version of behaviorism in the 1970s, and Skinner extended his approach to consider more and more complex behavior, including thought processes and language. His 1957 book Verbal Behavior, an example of this extrapolation, was reviewed by the linguist Noam Chomsky, who subjected it to devastating criticism (Chomsky 1959). Skinner declined to respond to Chomsky, and many individuals took this as a sign of the demise of behaviorism. This was not completely true, as can be seen in the current era of behaviorism, which features teleological behaviorism, interbehaviorism, empirical behaviorism, and so on (see O’Donohue and Kitchener 1999). Although behaviorism does not have the hegemony it once did, it continues to exist, but is restricted to pockets of research. Indeed, there are several scientific journals devoted to behaviorism, including the Experimental Analysis of Behavior and Behavior and Philosophy.
Philosophical Behaviorism Although psychological behaviorism can be described relatively clearly, philosophical behaviorism cannot. Fundamentally, a philosophical behaviorist is one who has a particular theory of the philosophical nature of the mind. All philosophical behaviorists are opposed to the Cartesian theory of mind: that the mind is a special kind of nonphysical substance that is essentially private, and introspection is the only or primary way of knowing about the contents of the mind, such that the individual has a privileged access to his mind. One or more of these tenets is denied by the philosophical behaviorist, who believes that there is nothing necessarily hidden about the mind: It is not essentially private, not made of a special substance, not known by any special method, and there is no privileged access to the mind.
In effect, the philosophical behaviorist claims that the mind is essentially something public, exemplified in one’s actions in the world, and that mentalistic properties are those displayed in certain kinds of public behavior. Such a view was championed by Bertrand Russell (1921, 1927; see Kitchener 2004). But what particularly distinguishes twentieth-century philosophical behaviorism is its commitment to semantic behaviorism, the view that philosophy is concerned with the analysis of the meaning of mentalistic terms, concepts, and representations. This “linguistic turn” in philosophy (Rorty 1967) means that instead of talking about the nature of the mind as an object in the world, philosophers should be concerned with our linguistic representations of the mind. This type of philosophical behaviorism is called logical (analytic, conceptual) behaviorism. Philosophical behaviorism, therefore, is different from psychological behaviorism.
Ludwig Wittgenstein is sometimes called a behaviorist, largely because he was critical of the Cartesian model of the mind, especially its assumption that the meaning of a mentalistic term must be given in terms of one’s private sensations or states of consciousness. Such an account would amount to a private language because only the individual can know the meaning of a mentalistic term, an Page 278 | Top of Articleitem of his necessarily private experience. Private languages are not possible according to Wittgenstein, because any language must (initially) be a public language; the meaning of mentalistic terms must be intersubjective and public (1953). In order to use a word correctly, Wittgenstein claimed, there must be public criteria for its correct employment. Most individuals insist that Wittgenstein’s kind of behaviorism is radically different from the psychological behaviorism of Watson and Hull. Whether it is fundamentally different from Skinner’s behaviorism is still an open question.
Gilbert Ryle is also sometimes characterized as an analytic or logical behaviorist. Also rejecting the Cartesian conception of the mind, Ryle showed that mentalistic terms have to have public criteria for their correct use, and hence that mentalistic terms and states are not essentially private to the individual, but must be understood (largely) as complex behavioral dispositions, or actions (and tendencies to act) in certain kinds of physical and social situations (1949). According to Ryle, therefore, mentalistic terms are to be understood in the same way we understand the meaning of, for example, the term punctual: An individual is punctual if she shows up to class on time, regularly meets her appointments, and so on. Ryle had strong reservations about calling his views “behavioristic,” largely because he thought behaviorism was committed to a mechanistic account of bodily movements and this was certainly not what behavior (or better, action) was.
As Ryle was influenced by Wittgenstein, so were other philosophical behaviorists. Rudolf Carnap and Carl Hempel were members of the group of philosophers known as logical positivists. According to a fundamental principle of logical positivism, the meaning of a statement consists of its method of verification. The meaning of a mentalistic term must be verifiable to be meaningful, and in principle, its meaning consists in how one verifies it by means of empirical observation. For example, the statement “Paul has a toothache” is (approximately) equivalent in meaning to the procedures one uses to verify that Paul has a toothache. Although this might consist in observing Paul’s physical behavior, it might also consist in observing the state of Paul’s tooth. Hence, for logical positivists, analytic behaviorism merged into the identity theory of mind and central state materialism—the view that mental states are central states of the brain. It remains unclear, therefore, to what extent they should be called “logical behaviorists”; certainly their version of logical behaviorism was quite different from Wittgenstein’s and Ryle’s.
The last notable philosophical behaviorist was Willard Quine, who was strongly influenced by Carnap (and Wittgenstein); nevertheless, his views are not easily assimilated with theirs. His views about meaning (and hence the meaning of mentalistic terms) were verificationist in spirit (because he was an epistemological behaviorist), but he did not share certain of Carnap’s views about how to give a behavioral translation of mental terms. It cannot be done atomistically, but only holistically: One cannot give the meaning of single mentalistic term by giving observational conditions for its use. Indeed, Quine was suspicious of the very notion of “meaning” because such things, if they do exist, would be difficult to reconcile with naturalism and physicalism, and therefore the meaning of a mentalistic term cannot be equivalent to some item of behavior. Quine was also skeptical of the very possibility of verifying a statement by means of a set of observations; scientific observation is a much more theoretical affair than this. Nevertheless, Quine insisted that any science is committed to the observation of behavior (epistemological behaviorism, evidential behaviorism), and hence that mentalistic terms are, in some sense, equivalent to behavior. This is, in part, due to the public nature of language (Quine 1960). We obviously do learn what words mean in the process of learning a language, but all of this occurs in the public arena. We are taught how to use words by our linguistic community: In the presence of a public object such as snow, we learn (by principles such as those indicated by Skinner) to utter the word snow. Hence, Quine’s behaviorism is sometimes called a linguistic behaviorism because he insisted that all we have to go on when we teach and learn a language is the public behavior of individuals. This is closely tied to the importance of empirical observation and verification. Furthermore, Quine was committed to semantic behaviorism, the view that the meaning of words is necessarily tied to (or consists of) public behavior. Meanings are, therefore, not “in the mind.” This is a close cousin to the logical behaviorism of earlier philosophers.
With the rise of computer science and artificial intelligence in the 1960s, an interesting question arose concerning how one could decide if a machine such as a computer was intelligent or not (i.e., whether it “had a mind”). Alan Turing proposed a test—the “Turing test”—for deciding this question (Turing 1950). Basically, the Turing test holds that if you cannot distinguish a computer from a human in terms of its behavior, for example by asking them both questions and reading their answers, then because the human is intelligent, it would be difficult to deny that the machine is intelligent too.
The Turing test raises the issue of behaviorism once more, this time in the context of computers: Is it the actual behavior of the computer that is decisive in ascribing intelligence to it, or are the internal workings of the computer (e.g., using a lookup table) important? Those who answer yes to the latter question might be considered mentalists rather than behaviorists (Block 1981). There is reason to believe that Turing himself thought the internal Page 279 | Top of Articleprocessing of the computer were important, something most behaviorists have never really denied.
OBJECTIONS TO BEHAVIORISM
Psychological behaviorism and philosophical behaviorism have been criticized since the beginning of the twentieth century.
Objection: Behaviorism Ignores or Denies Consciousness Critics charge that because the behaviorist focuses on behavior—and this means external behavior—he or she ignores or dismisses the private internal realm of consciousness.
Let us assume that consciousness does exist, that individuals are aware of their internal mental thoughts and sensations. The methodological behaviorist argues that this realm can be ignored (from a scientific point of view) by simply refusing to consider it. Radical behaviorists argue that behaviorism does not have to ignore this realm; instead, one can simply treat consciousness as internal behavior not unlike the behavior of one’s stomach when it digests food. Or, a behaviorist might reply that consciousness is not actual occurrent internal behavior, but rather a behavioral disposition. This is what we ordinarily mean when we say things such as, for example, “the cat is awake and thinking about the mouse.”
One property of consciousness that it is particularly difficult for the behaviorist to accommodate are qualia—the internal “feel” of certain mental states or events, like the taste of chocolate or the feeling of a sharp pain. A related problem is how a behaviorist can handle images, for example, the image I have of my morning breakfast.
Objection: Behaviorist Explanations Are Inadequate Most behaviorists take behavior as that which needs to be explained—why it occurs, what its form consists of, why it ceases, and so on. But what provides the explanation of such behavior? The standard answer is that stimuli—external stimuli—provide explanations, together with psychological principles concerning the relation of such stimuli to responses. But according to the critic, it remains doubtful that external stimuli can provide such all-encompassing explanations. Instead, one must refer to certain kinds of internal states—typically cognitive states—to explain the behavior.
A very sketchy behaviorist reply would be that all explanatory internal states—including all “cognitive” states—can be explained in terms of the ordinary concepts of stimulus and response, as long as these terms are suitably modified. This typically has taken the form of saying that there are internal states occurring between the external stimulus and the external response but that these internal states are understood to be internal stimuli and internal responses; for example, according to Hull, internal states might be fractional anticipatory goal responses together with sensory feedback from them. These internal mediating mechanisms are not popular by contemporary cognitive standards, but if behaviorism is to be a viable research program, it must clearly postulate such an internal mechanism or something analogous. Whether these behavioristic models are sufficiently cognitive or representational remains an open question.
Objection: The Behaviorist Concept of Behavior Is Inadequate According to one popular argument (Hamlyn 1953), the behaviorist sees ordinary behavior as a mechanistic, physical response, like the movement of an arm. But this is an inadequate conception of human behavior, which is better thought of as an action, such as waving, signaling, flirting, or gesturing. The behaviorist cannot handle this kind of conception because actions are not mechanistic but rather intentional, teleological, rule-governed, governed by social norms, and so on, and these are incompatible with the behavioristic program.
The standard behaviorist reply is to deny the distinction between movements and actions and/or to argue that the behaviorist has always been interested in actions (Kitchener 1977), and that such a concept is consistent with a causal account.
Objection: The Behaviorist Cannot Adequately “Analyze” or Define a Single Mentalistic Term by Means of a Set of Behaviors Logical behaviorists attempted to translate a mentalistic term such as belief into a corresponding set of behaviors, for example, a verbal response. But such a translation is only plausible if we assume other mental states in our account, for example, other beliefs, desires, and so on. Hence we have not gotten rid of mentalistic terms (Chisholm 1957; Geach 1957) because there is no term-by-term reduction or elimination.
This objection carries little weight because logical behaviorists such as Carnap and Hempel very early in their careers gave up such a term-by-term approach in favor of a more holistic, theoretical approach, and this commands a central place in Quine’s holistic behaviorism.
Objection: The Spartan Objection and the Dramaturgical Objection A mental state, such as pain, is not equivalent to a set of public behaviors because it is possible for one to be stoic about pain: I might be in intense pain but never show it because, say, it is not “macho” to show pain. Likewise, I might manifest pain behavior but not really be in pain, as when I simulate pain as an actor in a play. Hence pain behavior is neither sufficient nor necessary for being in pain (Putnam 1975).
Both of these objections assume a very naive, “peripheral” behaviorism in which the behavior in question is publicly observable. It is necessarily restrictive because behaviorists can hold more sophisticated forms involving “internal” (covert) behavior along with the inclusion of behavioral “dispositions.” Secondly, the behaviorist has insisted that one learns the meaning of the term pain and to use the word correctly only in the context of public behavior, a view shared by Wittgenstein, Carnap, Quine, Sellars, and Skinner. There must be public criteria for the correct use of pain. So originally a certain kind of behaviorism must be correct; later, we may learn how to suppress such behavior and to internalize it. The basis of this claim concerns the learning of language and is based on Wittgenstein’s arguments against a private language, or on arguments similar to his.
Few individuals would claim that behaviorism today enjoys the popularity it once had. Indeed, many (or most) argue that behaviorism is dead—both in psychology and in philosophy. The claim is easier to make with respect to psychology, particularly in the aftermath of the cognitive revolution. Nevertheless, the reports of the death of behaviorism are somewhat exaggerated. Not only are there viable and interesting research programs that are behavioristic in name, there are signs that even in cognitive science and cognitive psychology there is a reemergence of behaviorism, for example, in connectionism (neural nets), robotics, and dynamic systems theory. In fact, according to some, it remains unclear how cognitive psychology differs from behaviorism, since most behaviorists have also been concerned with central cognitive states. Still, psychological behaviorism is currently a minor opinion.
In philosophy the matter is somewhat different. This is because of the centrality of language learning in analytic philosophy, which seems to demand something like a rule-following conception that presupposes a public or social conception of behavior. This view is shared by those sympathetic to Ryle, Wittgenstein, or Quine. The logical behaviorism of Carnap and Hempel is passé because it was abandoned early in favor of a central state theory of mind. But although psychological behaviorism may have seen its day, philosophical behavior, in one form or another, still claims the strong allegiance of many philosophers (depending on how one characterizes behaviorism).
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