# An Outline of Philosophy/Chapter 3

In the present chapter I wish to consider the processes by which, and the laws according to which, an animal's original repertoire of reflexes is changed into a quite different set of habits as a result of events that happen to it. A dog learns to follow his master in preference to anyone else; a horse learns to know his own stall in the stable; a cow learns to come to the cow-shed at milking time. All these are acquired habits, not reflexes; they depend upon the circumstances of the animals concerned, not merely upon the congenital characteristics of the species. When I speak of an animal "learning" something, I shall include all cases of acquired habits, whether or not they are useful to the animal. I have known horses in Italy "learn" to drink wine, which I cannot believe to have been a desirable habit. A dog may "learn" to fly at a man who has ill-treated it, and may do so with such regularity and ferocity as to lead to its being killed. I do not use learning in any sense involving praise, but merely to denote modification of behaviour as the result of experience.
The manner in which animals learn has been much studied in recent years, with a great deal of patient observation and experiment. Certain results have been obtained as regards the kinds of problems that have been investigated, but on general principles there is still much controversy. One may say broadly that all the animals that have been carefully observed have behaved so as to confirm the philosophy in which the observer believed before his observations ​began. Nay, more, they have all displayed the national characteristics of the observer. Animals studied by Americans rush about frantically, with an incredible display of hustle and pep, and at last achieve the desired result by chance. Animals observed by Germans sit still and think, and at last evolve the solution out of their inner consciou ness. To the plain man, such as the present writer, this situation is discouraging. I observe, however, that the type of problem which a man naturally sets to an animal depends upon his own philosophy, and that this probably accounts for the differences in the results. The animal responds to one type of problem in one way and to another in another; therefore the results obtained by different investigators, though different, are not incompatible. But it remains necessary to remember that no one investigator is to be trusted to give a survey of the whole field.
The matters with which we shall be concerned in this chapter belong to behaviourist psychology, and in part to pure physiology. Nevertheless, they seem to me vital to a proper understanding of philosophy, since they are necessary for an objective study of knowledge and inference. I mean by an "objective" study one in which the observer and the observed need not be the same person; when they must be identical, I call the study "subjective". For the present we are concerned with what is required for understanding "knowledge" as an objective phenomenon. We shall take up the question of the subjective study of knowledge at a later stage.
The scientific study of learning in animals is a very recent growth; it may almost be regarded as beginning with Thorndike's Animal Intelligence, which was published in 1911. Thorndike invented the method which has been adopted by practically all subsequent American investigators. In this method an animal is separated from food, which he can see or smell, by an obstacle which he may overcome by chance. A cat, say, is put in a cage having a door with a handle which he may by chance push open with his nose. At first the cat makes entirely random movements, until he ​gets his result by a mere fluke. On the second occasion, in the same cage, he still makes some random movements, but not so many as on the first occasion. On the third occasion he does still better, and before long he makes no useless movements. Nowadays it has become customary to employ rats instead of cats, and to put them in a model of the Hampton Court maze rather than in a cage. They take all sorts of wrong turnings at first, but after a time they learn to run straight out without making any mistake. Dr. Watson gives averages for nineteen rats, each of which was put into the maze repeatedly, with food outside where the rat could smell it. In all the experiments care was taken to make sure that the animal was very hungry. Dr. Watson says: "The first trial required on the average over seventeen minutes. During this time the rat was running around the maze, into blind alleys, running back to the starting point, starting for the food again, biting at the wires around him, scratching himself, smelling this spot and that on the floor. Finally he got to the food. He was allowed only a bite. Again he was put back into the maze. The taste of the food made him almost frantic in his activity. He dashed about more rapidly. The average time for the group on the second trial is only a little over seven minutes; on the fourth trial not quite three minutes; from this point to the twenty-third trial the improvement is very gradual." On the thirtieth trial the time required, on the average, was about thirty seconds. This set of experiments may be taken as typical of the whole group of studies to which it belongs.
Thorndike, as a result of experiments with cages and mazes, formulated two "provisional laws", which are as follows:
"The Law of Effect is that: Of several responses made to the same situation, those which are accompanied or closely followed by satisfaction to the animal will, other things being equal, be more firmly connected with the situation, so that, when it recurs, they will be more likely to recur; those which are accompanied or closely followed by dis-
"The Law of Exercise is that: Any response to a situation will, other things being equal, be more strongly connected with the situation in proportion to the number of times it has been connected with that situation and to the average vigour and duration of the connections."
We may sum up these two laws, roughly, in the two statements: First, an animal tends to repeat what has brought it pleasure; second, an animal tends to repeat what it has often done before. Neither of these laws is at all surprising, but, as we shall see, there are difficulties in the theory that they are adequate to account for the process of learning in animals.
Before going further there is a theoretical point to be cleared up. Thorndike, in his first law, speaks of satisfac tion and discomfort, which are terms belonging to subjective psychology. We cannot observe whether an animal feels satisfaction or feels discomfort; we can only observe that it behaves in ways that we have become accustomed to interpret as signs of these feelings. Thorndike's law, as it stands, does not belong to objective psychology, and is not capable of being experimentally tested. This, however, is not so serious an objection as it looks. Instead of speaking of a result that brings satisfaction, we can merely enumerate the results which, in fact, have the character which Thorndike mentions, namely, that the animal tends to behave so as to make them recur. The rat in the maze behaves so as to get the cheese, and when an act has led him to the cheese once, he tends to repeat it. We may say that this is what we mean when we say that the cheese "gives satisfaction", or that the rat "desires" the cheese. That is to say, we may use Thorndike's "Law of Effect" to give us an objective definition of desire, satisfaction, and discomfort. The law should then say: there are situations such that animals tend ​to repeat acts which have led to them; these are the situations which the animal is said to "desire" and in which it is said to "find satisfaction". This objection to Thorndike's first law is, therefore, not very serious, and need not further trouble us.
Dr. Watson considers one principle alone sufficient to account for all animal and human learning, namely, the principle of "learned reactions". This principle may be stated as follows:
When the body of an animal or human being has been exposed sufficiently often to two roughly simultaneous stimuli, the earlier of them alone tends to call out the response previously called out by the other.
Although I do not agree with Dr. Watson in thinking this principle alone sufficient, I do agree that it is a principle of very great importance. It is the modern form of the principle of "association". The "association of ideas" has played a great part in philosophy, particularly in British philosophy. But it now appears that this is a consequence of a wider and more primitive principle, namely, the associa tion of bodily processes. It is this wider principle that is asserted above. Let us see what is the nature of the evidence in its favour.
Our principle becomes verifiable over a much larger field than the older principle owing to the fact that it is movements, not "ideas", that are to be associated. Where animals are concerned, ideas are hypothetical, but movements can be observed; even with men, many movements are involuntary and unconscious. Yet animal movements and unconscious involuntary human movements are just as much subject to the law of association as the most conscious ideas. Take, e.g., the following example (Watson, p. 33). The pupil of the eye expands in darkness and contracts in bright light; this is an involuntary and unconscious action of which we only become aware by observing others. Now take some person and repeatedly expose him to bright light at the same moment that you ring an electric bell. After a time the electric bell alone will cause his pupils to contract. ​As far as can be discovered, all muscles behave in this way. So do glands where they can be tested. It is said that a brass band can be reduced to silence by sucking a lemon in front of it, owing to the effect upon the salivary glands of its members; I confess that I have never verified this statement. But you will find the exact scientific analogue for dogs in Watson, p. 26. You arrange a tube in a dog's mouth so that saliva drops out at a measurable rate. When you give the dog food it stimulates the flow of saliva. At the same moment you touch his left thigh. After a certain length of time the touch on the left thigh will produce just as much saliva without the food as with it. The same sort of thing applies to emotions, which depend upon the ductless glands. Children at birth are afraid of loud noises, but not of animals. Watson took a child eleven months old, who was fond of a certain white rat; twice at the moment when the child touched the rat, a sudden noise was made just behind the child's head. This was enough to cause fear of the rat on subsequent occasions, no doubt owing to the fact that the adrenal gland was now stimulated by the substitute stimulus, just like the salivary glands in the dog or the trumpet player. The above illustrations show that "ideas" are not the essential units in association. It seems that not merely is "mind" irrelevant, but even the brain is less important than was formerly supposed. At any rate, what is known experimentally is that the glands and muscles (both striped and unstriped) of the higher animals exhibit the law of transfer of response, i.e. when two stimuli have often been applied together, one will ultimately call out the response which formerly the other called out. This law is one of the chief bases of habit. It is also obviously essential to our understanding of language: the sight of a dog calls up the word "dog", and the word "dog" calls up some of the responses appropriate to a real dog.
There is, however, another element in learning, besides mere habit. This is the element dealt with by Thorndike's "Law of Effect". Animals tend to repeat acts which have pleasant consequences, and to avoid such as have unpleasant ​consequences. But, as we saw a moment ago, "pleasant" and "unpleasant" are words which we cannot verify by objective observation. What we can verify by observation is that an animal seeks situations which in fact have had certain results, and avoids situations which in fact have had certain other results. Moreover, broadly speaking, the animal seeks results which tend to survival of itself or its offspring, and avoids results which tend in the opposite direction. This, however, is not invariable. Moths seek flames and men seek drink, though neither is biologically useful. It is only approximately, in situations long common, that animals are so adjusted to their environment as to act in a way which is advantageous from a biological standpoint. In fact, biological utility must never be employed as an explanation, but only noticed as a frequent characteristic, of the ways in which animals behave.
Dr. Watson is of the opinion that Thorndike's "Law of Effect" is unnecessary. He first suggests that only two factors are called for in the explanation of habit, namely, frequency and recency. Frequency is covered by Thorndike's "Law of Exercise", but recency, which is almost certainly a genuine factor, is not covered by Thorndike's two laws. That is to say, when a number of random movements have finally resulted in success, the more recent of these movements are likely to be repeated earlier, on a second trial, than the earlier ones. But Dr. Watson finally abandons this method of dealing with habit-formation in favour of the one law of "conditioned reflexes" or "learned reactions". He says (Behaviourism, p. 166):
"Only a few psychologists have been interested in the problem. Most of the psychologists, it is to be regretted, have even failed to see that there is a problem. They believe habit formation is implanted by kind fairies. For example, Thorndike speaks of pleasure stamping in the successful movement and displeasure stamping out the unsuccessful movements. Most of the psychologists talk, too, quite volubly about the formation of new pathways in the brain, as though there were a group of tiny servants of Vulcan ​there who run through the nervous system with hammer and chisel digging new trenches and deepening old ones. I am not sure that the problem when phrased in this way is a soluble one. I feel that there must come some simpler way of envisaging the whole process of habit formation or else it may remain insoluble. Since the advent of the conditioned reflex hypothesis in psychology with all of the simplifications (and I am often fearful that it may be an over-simplification!) I have had my own laryngeal processes [i.e. what others call "thoughts"] stimulated to work upon this problem from another angle."
I agree with Dr. Watson that the explanations of habit- formation which are usually given are very inadequate, and that few psychologists have realised either the importance or the difficulty of the problem. I agree also that a great many cases are covered by his formula of the conditioned reflex. He relates a case of a child which once touched a hot radiator, and afterwards avoided it for two years. He adds: "If we should keep our old habit terminology, we should have in this example a habit formed by a single trial. There can be then in this case no 'stamping in of the successful movement' and 'no stamping out of the un- successful movement.'" On the basis of such examples, he believes that the whole of habit-formation can be derived from the principle of the conditioned reflex, which he formulates as follows (p. 168):
Stimulus X will not now call out reaction R; stimulus Y will call out reaction R (unconditioned reflex); but when stimulus X is presented first and then Y (which does call out R) shortly thereafter, X will thereafter call out R. In other words, stimulus X becomes ever thereafter substituted for Y.
This law is so simple, so important, and so widely true that there is a danger lest its scope should be exaggerated, just as, in the eighteenth century, physicists tried to explain everything by means of gravitation. But when considered as covering all the ground, it seems to me to suffer from two opposite defects. In the first place, there are cases where no habit is set up, although by the law it should be. In ​the second place, there are habits which, so far as we can see at present, have a different genesis.
To take the first point first: the word "pepper" does not make people sneeze, though according to the law it should. Words which describe succulent foods will make the mouth water; voluptuous words will have some of the effect that would be produced by the situations they suggest; but no words will produce sneezes or the reactions appropriate to tickling. In the diagram given by Dr. Watson (p. 106), there are four reflexes which appear to be not sources of conditioned reflexes, namely sneezing, hiccoughing, blinking, and the Babinski reflex; of these, however, blinking, it is suggested (p. 99), may be really itself a conditioned reflex. There may be some quite straightforward explanation of the fact that some reactions can be produced by substitute stimuli while others cannot, but none is offered. Therefore the law of the conditioned reflex, as formulated, is too wide, and it is not clear what is the principle according to which its scope should be restricted.
The second objection to Dr. Watson's law of habit, if valid, is more important than the first; but its validity is more open to question. It is contended that the acts by which solutions of problems are obtained are, in cases of a certain kind, not random acts leading to success by mere chance, but acts proceeding from "insight", involving a "mental" solution of the problem as a preliminary to the physical solution. This is especially the view of those who advocate Gestaltpsychologie or the psychology of configuration. We may take, as typical of their attitude on the subject of learning, Köhler's Mentality of Apes. Köhler went to Tenerife with certain chimpanzees in the year 1913; owing to the war he was compelled to remain with them until 1917, so that his opportunities for study were ex- tensive. He complains of the maze and cage problems set by American investigators that they are such as cannot be ​solved by intelligence. Sir Isaac Newton himself could not have got out of the Hampton Court maze by any method except trial and error. Köhler, on the other hand, set his apes problems which could be solved by what he calls insight". He would hang up a banana out of reach, and leave boxes in the neighbourhood so that by standing on the boxes the chimpanzees could reach the fruit. Sometimes they had to pile three or even four boxes on top of each other before they could achieve success. Then he would put the banana outside the bars of the cage, leaving a stick inside, and the ape would get the banana by reaching for it with the stick. On one occasion, one of them, named Sultan, had two bamboo sticks, each too short to reach the banana; after vain efforts followed by a period of silent thought, he fitted the smaller into the hollow of the other, and so manufactured one stick which was long enough. It seems, however, from the account, that he first fitted the two together more or less accidently, and only then realised that he had found a solution. Nevertheless, his behaviour when he had once realised that one stick could be made by joining the two was scarcely Watsonian: there was no longer anything tentative, but a definite triumph, first in anticipation and then in action. He was so pleased with his new trick that he drew a number of bananas into his cage before eating any of them. He behaved, in fact, as capitalists have behaved with machinery.
Köhler says: "We can, from our own experience, distinguish sharply between the kind of conduct which, from the very beginning, arises out of a consideration of the characteristics of a situation, and one that does not. Only in the former case do we speak of insight, and only that behaviour of animals definitely appears to us intelligent which takes account from the beginning of the lie of the land, and proceeds to deal with it in a smooth continuous course. Hence follows this characteristic: to set up as the ​criterion of insight, the appearance of a complete solution with reference to the whole lay-out of the field."
Genuine solutions of problems, Köhler says, do not improve by repetition; they are perfect on the first occasion, and, if anything, grow worse by repetition, when the excite- ment of discovery has worn off. The whole account that Köhler gives of the efforts of his chimpanzees makes a totally different impression from that of the rats in mazes, and one is forced to conclude that the American work is somewhat vitiated by confining itself to one type of problem, and drawing from that one type conclusions which it believes to be applicable to all problems of animal learning. It seems that there are two ways of learning, one by experience, and the other by what Köhler calls "insight". Learning by experience is possible to most vertebrates, though rarely, so far as is known, to invertebrates. Learning by "insight", on the contrary, is not known to exist in any animals lower than the anthropoid apes, though it would be extremely rash to assert that it will not be revealed by further observations on dogs or rats. Unfortunately, some animals—for instance, elephants—may be extremely intelligent, but the practical difficulty and expense of experimentation with them is so great that we are not likely to know much about them for some time to come. However, the real problem is already sufficiently definite in Köhler's book it is the analysis of "insight" as opposed to the method of the conditioned reflex.
Let us first be clear as to the nature of the problem, when described solely in terms of behaviour. A hungry monkey, if sufficiently near to a banana, will perform acts such as, in circumstances to which it has been accustomed, have previously enabled it to obtain bananas. This fits well with either Watson or Thorndike, so far. But if these familiar acts fail, the animal will, if it has been long without food, is in good health, and is not too tired, proceed to other acts which have never hitherto produced bananas. One may suppose, if one wishes to follow Watson, that these new acts are composed of a number of parts, each of ​which, on some former occasion, has occurred in a series which ended with the obtaining of the banana. Or one may suppose—as I think Thorndike does—that the acts of the baffled animal are random acts, so that the solution emerges by pure chance. But even in the first hypothesis, the element of chance is considerable. Let us suppose that the acts A, B, C, D, E have each, on a former occasion, been part of a series ending with success, but that now for the first time it is necessary to perform them all, and in the right order. It is obvious that, if they are only combined by chance, the animal will be lucky if it performs them all in the right order before dying of hunger.
But Köhler maintains that to anyone watching his chimpanzees it was obvious they did not obtain "a composition of the solutions out of chance parts". He says (pp. 199-200):
"It is certainly not a characteristic of the chimpanzee, when he is brought into an experimental situation, to make any chance movements, out of which, among other things, a non-genuine solution could arise. He is very seldom seen to attempt anything which would have to be considered accidental in relation to the situation (excepting, of course, if his interest is turned away from the objective to other things). As long as his efforts are directed to the objective, all distinguishable stages of his behaviour (as with human beings in similar situations) tend to appear as complete attempts at solutions, none of which appears as the produce of accidentally arrayed parts. This is true, most of all, of the solution which is finally successful. Certainly it often follows upon a period of perplexity or quiet (often a period of survey), but in real and convincing cases the solution never appears in a disorder of blind impulses. It is one continuous smooth action, which can be resolved into its parts only by the imagination of the onlooker; in reality they do not appear independently. But that in so many 'genuine' cases as have been described, these solutions as wholes should have arisen from mere chance, is an entirely inadmissible supposition."
​Thus we may take it as an observed fact that, so far as overt behaviour is concerned, there are two objections to the type of theory with which we began, when considered as covering the whole field. The first objection is that in cases of a certain kind, the solution appears sooner than it should according to the doctrine of chances; the second is that it appears as a whole, i.e. that the animal, after a period of quiescence, suddenly goes through the right series of actions smoothly, and without hesitation.
Where human beings are concerned, it is difficult to obtain such good data as in the case of animals. Human mothers will not allow their children to be starved, and then shut up in a room containing a banana which can only be reached by putting a chair on the table and a footstool on the chair, and then climbing up without breaking any bones. Nor will they permit them to be put into the middle of a Hampton Court maze, with their dinner getting cold outside. Perhaps in time the State will perform these experiments with the children of political prisoners, but as yet, perhaps fortunately, the authorities are not sufficiently interested in science. One can observe, however, that human learning seems to be of both sorts, namely, that described by Watson and that described by Köhler. I am persuaded that speech is learnt by the Watsonian method, so long as it is confined to single words: often the trial and error, in later stages, proceeds sotto voce, but it takes place overtly at first, and in some children until their speech is quite correct. The speaking of sentences, however, is already more difficult to explain without bringing in the apprehension of wholes which is the thing upon which Gestaltpsychologie lays stress. In the later stages of learning, the sort of sudden illumination which came to Köhler's chimpanzees is a phenomenon with which every serious student must be familiar. One day, after a period of groping bewilderment, the schoolboy knows what algebra is all about. In writing a book, my own experience—which I know is fairly common, though by no means universal—is that for a time I fumble and hesitate, and then suddenly I see the book as a whole, and have ​only to write it down as if I were copying a completed manuscript.
If these phenomena are to be brought within the scope of behaviourist psychology, it must be by means of "implicit" behaviour. Watson makes much use of this in the form of talking to oneself, but in apes it cannot take quite this form. And it is necessary to have some theory to explain the success of "implicit" behaviour, whether we call it "thought" or not. Perhaps such a theory can be constructed on Watson's lines, but it has certainly not yet been constructed. Until the behaviourists have satisfactorily explained the kind of discovery which appears in Köhler's observations, we cannot say that their thesis is proved. This is a matter which will occupy us again at a later stage; for the present let us preserve an open mind.
* ↑ Dr. Watson apparently entertains hopes of teaching babies to sneeze when they see the pepper box, but he has not yet done so. See Behaviourism, p. 90.
* ↑ Called by Köhler "the objective", because the word "banana" is too humble for a learned work. The pictures disclose the fact that "the objective" was a mere banana.