Mechanists Duplicate the Phenomena Of Life,
but the Vitalists Still Cling To a Mystical Philosophy

THERE are twenty-six letters in the alphabet.  They are found in the words of Shakespeare and of any political orator.  Whether we have great literature or mediocre thinking is a matter of arranging the letters into words and the words into phrases and sentences.

Similarly there are ninety-two elements.  Depending on how we arrange them we have an inanimate stone or a man.  The ultimate kind of matter in man and in the stone is the same.

Go down in the scale of life and you find that cells behave more and more like familiar bits of matter responding to external physical forces.  In fact the lower we go the more the organism becomes part of its environment.  A bit of dead matter becomes indistinguishable from a living cell so far as its mere behavior is concerned.  A cell becomes in terms of biology a "physico-chemical system."

Put some chloroform on a hardened shellac surface.  The drop moves about like an amoeba.  "Surface tension," exclaims the physicist.  "The force that enables insects to walk on water and causes rain to collect in little globules on a waterproof cloth."  Bring a drop of chloroform near a glass particle coated with shellac.  The drop flows around the particle, devours and digests the shellac, and then, most wonderful of all, actually rejects the indigestible glass particle.  A living amoeba can do no more.

***

EVERY phenomenon of life can be duplicated in the laboratory -- even reproduction, as we see in the case of crystals that grow like plants.  And yet it is not possible to say that these bits of inanimate matter which stir, eat, reproduce themselves are really alive.  There is a vast difference between a bit of protoplasm, the simplest kind of life, and a drop of chloroform in contact with shellac.

Go up the scale and the difference between living and non-living is so marked that there is no possibility of confusion.  A man is more or less independent of his environment.  But why?  He, too, is protoplasm -- a highly complex system of cells.

In efforts to explain him, two schools of thought have been engaged in controversy for generations.  "A creature set apart by a soul, by consciousness, by free will," assert the vitalists.  "Bosh!" retort the mechanists.  "A man is simply a physico-chemical system, like the amoeba, only much more complex.  There is no soul.  If man seems to have free will and consciousness it is because his responses to his surroundings are difficult to fathom.  The more biology and psychology discover about man, the more machinelike he becomes."

It is hard to put these theories to the test simply because there is still something sacred about the human being.  Vesalius was persecuted in his time because he dissected a corpse.  No physician or biologist would today experiment with a baby before he had made sure of his ground with the aid of animals.  And there are laws enough to restrain the biologist in his utilization of animals.

The mechanistic theory can be tested in two ways.  One is to study and train twins, and the other is to construct machines that will display the cruder aspects of human behavior.

We begin with the twins.  They must be what are called "identical" twins.  That is, they must be so alike that their own mother can hardly tell them apart.  They result from the fertilization of a single human egg.  Alike in physique, in coloring, in mentality, they begin life under the same conditions.  They resemble each other as do cuttings of the same plant.  If there is anything like free will, independence of environment, their lives ought to be identical.

We consider Johnny and Jimmy, identical twin infant sons of a telephone operator and a taxicab driver.  Ever since they have been twenty days old Dr. Myrtle B. McGraw of the Neurological Institute has had them in her scientific charge.  Every morning they are taken to the institute.  Johnny, who was slightly weaker at birth and therefore at a disadvantage, has been trained.  He roller-skates, he dives into a pool and swims, he climbs up ladders and inclined planes, he looks calmly over the edge of a high shelf to which he has been lifted, lets himself down as far as his arms will reach and drops to the floor.  Twenty months old, he is more of an athlete and displays more courage than we have a right to expect of a child of his age.

Gaze now upon Jimmy, who has been left to his own devices.  Place him on the high shelf and he yowls with fear and looks down appealingly for aid.  Tell him to get a hat or a spoon and he simply coos uncomprehendingly.  Johnny, his trained brother, gets them.  He seems two or three times as bright and able.

Here we have two living, intelligent children as alike as they can be at birth and yet differing profoundly after a year's training of one of them.

***

BUT it is doubtful if we shall ever arrive at the truth by studying identical twins even in this fashion.  If man is a machine, then it ought to be possible for the biologist, when he has learned enough and made himself a good enough engineer and inventor, to become a Frankenstein and create a machine which will be without soul or spirit, but which will behave as if it were human.  The attempt has already been made by about a score of scientists.

A few weeks ago a student at Massachusetts Institute of Technology, Norman B. Krim, stood up before the Cambridge section of the American Institute of Electrical Engineers and read a paper which bore the harmless and uninspiring title, "An Electro-Mechanical Analogue of the Conditioned Reflex."  His contrivance could learn and forget.  It consisted of nothing more than a rheostat (like the controller whereby a motorman turns on the current of a trolley car), some switches, an ordinary incandescent lamp and wires connecting all these elements into a simple circuit which could in turn be connected with the light circuit of any house.

Robot?  There is no more abused word.  Linotype machines, calculators, mechanisms that displace human muscles -- all are called robots.  These devices are as monotonous as clocks.  An automatic elevator will not stop of its own accord at your office floor even though you may have used it a thousand times.  The operator must set the stopping mechanism.  There is nothing human about automatic machines.  They are merely extensions of ourselves -- senses that supplement our eyes and ears under our control, muscles that do our bidding.  Of "voluntary" action not a sign.

But Krim's machine is different.  It can be animated into a semblance of "consciousness" and it can relapse into unresponsiveness.

Krim made it clear in his paper that he was inspired by the pioneer work of Professor Clark L. Hull of Yale University and his group of research associates.  At Yale four devices have been built which remember and forget.

The inventors have no illusions about themselves or their models.  It is not the object of Professor Hull or these young men to pose as Frankensteins who will some day produce real robots of the type that Capek exhibited in his satirical play, nor are they especially concerned with anything practical in the business sense.  All of them are confirmed mechanists.

In other words, they are convinced that "mind," "soul" and "spirit" are meaningless terms inherited from a mystic past and that a human being, whether he be an Einstein or an imbecile, is simply a highly complex organization of matter which happens to be what we call "alive," but which will ultimately be explained in terms of physics, chemistry and electricity.  In fact, the whole purpose of the models built by Krim and by Professor Hull and his group is to support the thesis that man is indeed an automaton -- a creature that has learned to respond in definite ways to external and internal forces, after which it acts with genuine spontaneity whenev[e]r these same forces in the proper sequence or combination play upon senses and nervous systems.

Note the title of Krim's paper -- "An Electro-Mechanical Analogue of the Conditioned Reflex."  Note other papers on "An Electrochemical Parallel to the Conditioned Reflex" (by Robert G. Krueger and Clark L. Hull), "A Mechanical Model of the Conditioned Reflex" (by H. D. Baernstein and Clark L. Hull), "A Model of the Synthesis of Conditioned Reflexes" (by G. K. Bennett and L. B. Ward).  Every title contains the words "conditioned reflexes."  Which brings us to the eminent, Russian physiologist Ivan P[etrovich] Pavlov [1849-1936], founder of this new school of psychologists to whom mind, consciousness and soul are anathema when invoked to explain why we behave like human beings.

***

A GOODLY part of Pavlov's life has been spent in studying dogs or, rather, the circumstances in which a dog's mouth will water when it is about to eat.  As soon as a dog sees food the watering begins.  It is a reflex action something over which the animals has no control.  Human beings have reflexes, too.  Throw one leg over the other.  Tap the upper leg just below the knee and it will kick involuntarily.  Reflex action again.  Winking, swallowing about everything that used to be summed up in the all-embracing but scientifically disreputable term "instinct," is now explained as a reflex or a collection of reflexes.

Involuntary reflexes -- the watering of the dog's mouth when food is presented -- are called "unconditioned" by Pavlov.  There are other reflexes which are the result of training and which always occur when the conditions are right or under control.  These are Pavlov's now famous "conditioned reflexes."

Consider one of Pavlov's dogs and learn just what is meant by conditioned reflexes.  Pavlov rings a bell or starts a metronome ticking when he feeds the dog.  Sound and food are associated.  After a time the dog's mouth drips when he hears the bell and sees the food.  Finally the ringing of the bell without the presenting of any food at all brings about the same effect.  The bell which originally produced no observable reaction, perhaps, has not acquired an excitatory power.  The dog has learned by experience or "association," as the old-fashioned psychologists would say.  But this ringing of the bell and withholding of food cannot be kept up indefinitely without affecting the dog's reflexes.  Fooled often enough, his salivary glands will no longer water.  His conditioned reaction is now said to be "inhibited."

Pavlov varies this experiment in dozens of different ways.  He builds up responses of avoidance by mixing disagreeable acids with food and ringing a bell at feeding time.  Thus he proves how easy it is to cultivate defense reactions.  He reduces dogs to a state of hysteria by conditioning them in various conflicting ways.  Thus he trained one animal to associate a bright circular patch of light with food and an ellipse with an electrical shock.  Soon there were yelps of joy at the sight of a circle and a flow of saliva, but growls of fear when the ellipse was seen.  Gradually Pavlov made the ellipse resemble the circle more and more.  The dog was reduced almost to a nervous wreck, unable to do more than howl and struggle.

The beauty of Pavlov's experimenting ties in its thorough objectivity.  It is not what a man or a dog is thinking about that is important, but what he does.  No mistake in this is possible.  Hundreds of experiments have led Pavlov to the conclusion that different kinds of habits, based on training, discipline and education of any kind, are nothing but a snarl of conditioned reflexes.  Associations once established become automatic and are persistently reproduced.

***

THERE are two elements in every reflex.  First the pulling of the trigger, as it were -- the stimulus.  Then the reaction or response -- what happens when the trigger is pulled or the stimulus allowed to operate.  You put your hand in the dark.  Something pricks your finger -- the stimulus.  You jerk your hand back -- the response.  You have demonstrated what an unconditioned reflex is.  If your fingers were always pricked when you put out your hand in the dark you would soon be conditioned.  In other words, you would feel the prick of pain without being jabbed by a point, just because you were in the dark.

Is the body, then, a mere machine governed wholly by forces -- what the psychologist calls "stimuli"?  Pavlov and his school believe so.  Moreover, Dr. John B[roadus] Watson [American psychologist, (1878-1958)] has constructed a whole psychology of behavior on the theory that, by conditioning or training, the complex human being can be taught to be and to do almost anything.  If this is correct (even adherents of Pavlov have their doubts), then it is idle to seek the greatness of Lincoln, Edison or Einstein in unique combinations of cells or in their heredity.  They become merely living machines which have been accidentally conditioned to produce social policies of great moment, electric lamps and phonographs, and theories of a universe in which space is curved and time is a dimension.

Love, heroism, hatred, fear are not denied.  The mechanist merely says:  "Show me behavior to which you apply the adjectives loving and heroic, and I will initiate a series of experiments which some day will make it possible to draw predictable conclusions about love and heroism."

Once this purely mechanistic conception of behavior is accepted the next step is obvious.  Build something that will behave like an animal even if in the crudest fashion.  It need not have a mouth to secret saliva or a knee tendon that can be made to jerk automatically.  All that is required is some combination of mechanical, electrical or chemical elements that will respond to a stimulus after a brief education. Hence the inventions that Professor Hull has inspired.  Do not look for something that even remotely resembles a dog.

An eagle is a living airplane which is adapted not only to flying but to living, breathing, fighting, eating, preserving the species. He is far more complex than an airplane need be -- a machine which has only to fly for a certain number of hours and carry its passengers safely.  It is the end result that counts -- in this case flying.  Yet technically there is a real resemblance in principle between the eagle and the airplane so far as support and propulsion are concerned.  So with the imitations that have been built under Professor Hull's direction.  They are not alive.  All that is expected of them is to illustrate a principle, a theory of the essentially mechanical nature of intelligent organisms.

***

AT first glance you would never recognize in the score of models thus far built contrivances that duplicate a few simple types of human behavior.  It is useless to describe them in detail here.  We are interested in what they do, in what they prove, in their relation to our own adaptation to our surroundings.

To construct one of these analogues we must have some knowledge or at least some theory of the mechanism involved in reflex action, conditioned and unconditioned.  How do mechanists or behaviorists explain what happens when the dog sees food and his salivary glands begin to water involuntarily?  The eye sends some message to the brain.  Salivary glands, tongue, jaws, legs, perhaps fifty different members and organs, are thereupon ordered by the brain to do something.  A connection ahs been established between the sensory centres of the brain and the eye on the one hand and other motor centres that control glands, jaws and legs on the other.  Moreover, it has been conclusively demonstrated by the work of Professor Sherrington in England that nerve impulses are electrical in their nature.

With these few facts to guide us we cannot go far wrong if we construct a simple electric circuit which includes a battery, a push button and a lamp.  Push the button.  That is the equivalent of showing food to the dog -- the stimulus.  The lamp lights up.  That is the response -- the equivalent of mouth-watering.

We return to our dog.  He has been conditioned by repeatedly hearing the bell ring in connection with the presentation of food, so that his mouth waters at the mere ringing.  How is that to be explained?  There is no direct connection between eye and ear.  But there is to the cortex of the brain.  To call it a switchboard is only partly correct.  Actually it is a correlation centre, a clearing house.  Every time the bell is rung indirect connections between ear and eye are simultaneously excited.  The correlation centre or clearing house receives two nervous impulses or messages at once. Presently the ear's message alone is enough to make the  mouth water.  In fact the "thinking" part of a dog's brain can be cut out, and he will still learn to associate eye and ear messages and ultimately to act on the ear's message alone.

The next step in building our analogue is to take account of this process.  You install another circuit, another push button, another lamp.  Push this second button, and nothing happens.  It is just as if the bell had been rung for the first time, with no effect on the dog's salivary glands.  Push both the first and the second buttons together and both lamps glow.  You have the equivalent of showing a dish of food and ringing the bell.

Keep on pushing both buttons and making both lamps glow.  You are training the apparatus -- teaching it associations.  Do this a dozen times.  See now what happens.  You push the second button alone -- the "bell button" -- and the first or "mouth-watering" lamp glows.  The two electric circuits have been deliberately constructed to this end with the aid of what the engineer calls a battery of polarizable cells.  We need not bother about details of construction.  It suffices to know that just as in the case of the brain we have succeeded in switching in pulses or signals from a roundabout course to a direct course.

But this is not all.  We keep on pushing the second, or "bell ringing" button alone.  Soon the "mouth-watering" lamp refuses to glow.  The apparatus is now unconditioned.  Like a dog, it can be tricked only a certain number of times, whereupon it relapses into its unconditioned state.  But, like a dog, it can be conditioned by a new course of training or associations -- the pressing of the two buttons simultaneously.

***

WE have here the essentials of an invention of Robert G. Krueger and Professor Hull -- what they call "an electro-chemical parallel to the conditioned reflex."  There are many variants of which Krim's is but one.  G. K. Bennet and L. B. Ward of Professor Hull's laboratory staff are designing an apparatus which will thread a maze like a rat, but only after making and correcting many mistakes and literally persisting until it learns the right path.

Krim has invented a combination of two photoelectric cells, or "eyes," responsive to red and green; variable speed motors, variable resistances, vacuum-tube amplifiers, relays and switches.  The whole can be constructed for $200.  To teach the lesson of conditioned and unconditioned reflexes as dramatically and as humanly as possible, Krim puts all these parts in a head and bust mounted on a car.  Current (nervous energy) is supplied through the track on which the bust runs.

Ring a bell.  The robot ignores it.  Hold out beets, then spinach.  Still no response.  Now pull the robot across the room when the bell is rung.  Do this ten times.  When the bell is rung the eleventh time the robot slowly runs on the track across the room by itself.  Give it more "lessons" and it will run more rapidly.

Hold out spinach before its electric eye and pull its ears.  After ten such lessons it will shake its head from side to side slowly at the mere sight of spinach.  More lessons are followed by a more active shaking of the head in seeming "dislike."

Hold out beets before the electric eye and stroke the top of the robot's head.  After ten lessons the head will nod slowly at the sight of beets and still more approvingly with more conditioning.

If these three stimuli -- sound of bell, sight of spinach, sight of beets -- are again applied after twenty-four hours, the robot will respond to the bell but not to either vegetable.  It can then be conditioned to "like" spinach (indicated by nodding) and to "dislike" beets.

To be sure, the robot will behave in the same way if, instead of spinach or beets, green and red cardboard are exhibited.  Color is a factor in our liking and disliking food, although taste is perhaps more important.  The point is that we re concerned with actual behavior and not with speculation about "thinking."

***

COMPARED with this crude apparatus, an amoeba is extraordinarily complex, although it is perhaps the simplest one-celled form of life.  It is conceivable that  an electrical apparatus might be constructed which would behave much like an amoeba -- move through water, wrap itself around food, digest the food, expel what it does not want and divide at least once in an effort to reproduce itself after the manner of cells.  But the contrivance would have to be a maze of circuits and electromagnets as big as a motor truck.

Think, then, what is involved in constructing an artificial creature which would be a real robot like any in Capek's play.  To reproduce anything like the brain is an impossible task.  The human cerebral cortex alone contains an estimated 9,200 million nerve cells, and these are interconnected in billions of possible ways.  Our Frankenstein would have to be superarchitect, engineer, chemist, physicist, mechanic, plumber and electrician.  His robot would be as big as the Empire State Building.  It would cost hundreds of millions if he could construct it at all.

"How successful the attempts to construct 'psychic' machines will prove, time alone can tell," says Professor Hull.  "It will be too early to venture a final judgment until as much labor and ingenuity have been expended in the attempt as have been devoted to the development of the steam engine, the electric motor or the printing processes."  Still he sees possibilities.  "It is not inconceivable that in the demands of higher and higher degree of automaticity in machines in industry the ultra-automaticity of the machine that can be conditioned may have an important place."

If you recoil from this conception of man let Pavlov try to convince you that you are not degraded and that perhaps the race may achieve a higher destiny because all that we sum up in emotion, consciousness, love and nobility will ultimately be explained in terms of mechanism, chemical reactions, electrical effects and other responses to the external world.  Listen:

I am deeply and irrevocably convinced that along this path will be found the final triumph of the human mind over its uttermost and supreme problem -- the knowledge of the mechanism and laws of human nature.  Only thus may come a full, true and permanent happiness.

Let the mind rise from victory to victory over surrounding nature, let it conquer for human life and activity not only the surface of the earth but all that lies between the depth of the seas and the outer limits of the atmosphere, let it command for its service prodigious energy to flow from one part of the universe to the other, let it annihilate space for the transference of its thoughts -- yet the same human creature, led by dark powers to wars and revolutions and their horrors, produces for itself incalculable material losses and inexpressible pain, and reverts to bestial conditions.

Only science, exact science about human nature itself, and the most sincere approach to it by the aid of the omnipotent scientific method, will deliver man from his present gloom, and will purge him from his contemporary shame in the sphere of interhuman relations.

Inspiring as this may be, the vitalists decline to be moved.  Their position is thus defined by Dr. J. S. Haldane [Scottish physiologist, John Scott Haldane (1860-1936); but Kaempffert is probably referring to Haldane's son, geneticist John Burdon Sanderson Haldane (1892-1964) author of the acclaimed text, The Causes of Evolution (1932)]:

We can, of course, leave the characteristic peculiarities of conscious behavior out of our account, and regard persons from a purely physical and chemical point, as weighing so much, as yielding certain amounts of various proteins and other chemical substances, distributed in a certain way, and as in various ways continually converting potential into kinetic energy.  This mode of regarding persons is of great practical purpose for engineering and other purposes, but tells us nothing, however far we may extend it, regarding the distinctive characters of conscious behavior.

In other words, Dr. Haldane would object to the machines of Professor Hull as analogues of some types of human behavior because they are not consciously responding to button-pushing.  A mechanist would find the reply inadequate in the light of Pavlov's work.  His whole purpose is to break down consciousness into its hundreds of separate reflexes.