Burnham, “On the origins of behaviorism.” Journal of the History of the Behavioral Sciences, 1968, 4: 143-151. And for a good discussion, Richard Herrnstein’s “Introduction to John B. Watson’s Comparative Psychology” in Historical Conceptions of Psychology, M. Henle, J. Jaynes, and J. J. Sullivan, eds. (New York: Springer, 1974), 98 —115.
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wary of subjective thought and longed for objective fact. And in America objective fact was pragmatic fact. Behaviorism provided this in psychology. It allowed a new generation to sweep aside with one impatient gesture all the worn-out complexities of the problem of consciousness and its origin. We would turn over a new leaf. We would make a fresh start.
And the fresh start was a success in one laboratory after another. But the single inherent reason for its success was not its truth, but its program. And what a truly vigorous and exciting program of research it was! with its gleaming stainless-steel promise of reducing all conduct to a handful of reflexes and conditional responses developed from them, of generalizing the spinal reflex terminology of stimulus and response and reinforcement to the puzzles of headed behavior and so seeming to solve them, of running rats through miles and miles of mazes into more fascinating mazes of objective theorems, and its pledge, its solemn pledge to reduce thought to muscle twitches and personality to the woes of Little Albert.14 In all this there was a heady excitement that is difficult to relate at this remove. Complexity would be made simple, darkness would be made light, and philosophy would be a thing of the past.
From the outside, this revolt against consciousness seemed to storm the ancient citadels of human thought and set its arrogant banners up in one university after another. But having once been a part of its major school, I confess it was not really what it seemed. Off the printed page, behaviorism was only a refusal to talk about consciousness. Nobody really believed he was not conscious. And there was a very real hypocrisy abroad, as those interested in its problems were forcibly excluded from academic psychology, as text after text tried to smother the unwanted problem from student view. In essence, behaviorism was a method, not the theory that it tried to be. And as a method, it 14 The unfortunate subject of Watson's experiments on conditioned fear.
16
Introduction
exorcised old ghosts. It gave psychology a thorough house clean-ing. And now the closets have been swept out and the cupboards washed and aired, and we are ready to examine the problem again.
Consciousness as the Reticular Activating System But before doing so, one final approach, a wholly different approach, and one that has occupied me most recently, the nervous system. How often in our frustrations with trying to solve the mysteries of mind do we comfort our questions with anatomy, real or fancied, and think of a thought as a particular neuron or a mood as a particular neurotransmitter! It is a temptation born of exasperation with the untestableness and vagueness of all the above solutions. Away with these verbal subtleties!
These esoteric poses of philosophy and even the paper theories of behaviorists are mere subterfuges to avoid the very material we are talking about! Here we have an animal — make him a man if you will — here he is on the table of our analysis. If he is conscious, it has to be here, right here in him, in the brain in front of us, not in the presumptuous inklings of philosophy back in the incapable past! And today we at last have the techniques to explore the nervous system directly, brain to brain. Somewhere here in a mere three-and-a-half pound lump of pinkish-gray matter, the answer has to be.
All we have to do is to find those parts of the brain that are responsible for consciousness, then trace out their anatomical evolution, and we will solve the problem of the origin of consciousness. Moreover, if we study the behavior of present-day species corresponding to various stages in the development of these neurological structures, we will be able at last to reveal with experimental exactness just what consciousness basically is.
Now this sounds like an excellent scientific program. Ever since Descartes chose the brain’s pineal body as the seat of consciousness and was roundly refuted by the physiologists of his
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day, there has been a fervent if often superficial search for where in the brain consciousness exists.15 And the search is still on.
At the present, a plausible nominee for the neural substrate of consciousness is one of the most important neurological discoveries of our time. This is that tangle of tiny internuncial neurons called the reticular formation, which has long lain hidden and unsuspected in the brainstem. It extends from the top of the spinal cord through the brainstem on up into the thalamus and hypothalamus, attracting collaterals from sensory and motor nerves, almost like a system of wire-tabs on the communication lines that pass near it. But this is not all. It also has direct lines of command to half a dozen major areas of the cortex and probably all the nuclei of the brainstem, as well as sending fibers down the spinal cord where it influences the peripheral sensory and motor systems. Its function is to sensitize or “awaken”
selected nervous circuits and desensitize others, such that those who pioneered in this work christened it “the waking brain”16
The reticular formation is also often called by its functional name, the reticular activating system. It is the place where general anesthesia produces its effect by deactivating its neurons.
Cutting it produces permanent sleep and coma. Stimulating it through an implanted electrode in most of its regions wakes up a sleeping animal. Moreover, it is capable of grading the activity of most other parts of the brain, doing this as a reflection of its own internal excitability and the titer of its neurochemistry. There are exceptions, too complicated for discussion here. But they are not such as to diminish the exciting idea that this disordered network of short neurons that connect up with the entire brain, this central transactional core between the strictly sensory and motor systems of classical neurology, is the long-sought answer to the whole problem.
* * *
15 I have discussed this at greater length in my paper, “The Problem of Animate Motion in the Seventeenth Century,”
Journal of the History of Ideas,
1970, 31: 219-234.
16 See H. W. Magoun, The Waking Brain (Springfield, Illinois: Thomas, 1958).
18
Introduction
If we now look at the evolution of the reticular formation, asking if it could be correlated with the evolution of consciousness, we find no encouragement whatever. It turns out to be one of the oldest parts of the nervous system. Indeed, a good case could be made that this is the very oldest part of the nervous system, around which the more orderly, more specific, and more highly evolved tracts and nuclei developed. The little that we at present know about the evolution of the reticular formation does not seem to indicate that the problem of consciousness and its origin will be solved by such a study.
Moreover, there is a delusion in such reasoning. It is one that is all too common and unspoken in our tendency to translate psychological phenomena into neuro-anatomy and chemistry.
We can only know in the nervous system what we have known in behavior first. Even if we had a complete wiring diagram of the nervous system, we still would not be able to answer our basic question. Though we knew the connections of every tickling thread of every single axon and dendrite in every species that ever existed, together with all its neurotransmitters and how they varied in its billions of synapses of every brain that ever existed, we could still never — not ever — from a knowledge of the brain alone know if that brain contained a consciousness like our own.