The common spider will suspend its web on three, four, and up to twelve handy points of attachment, depending on the lie of the land, but the radial threads will always intersect the laterals at equal angles, according to a fixed code of rules built into the spider's nervous system; and the centre of the web will always be at its centre of gravity. The matrix -- the web-building skill -- is flexible: it can be adapted to environmental conditions; but the rules of the code must be observed and set a limit to flexibility. The spider's choice of suitable points of attachment for the web are a matter of strategy, depending on the environment, but the form of the completed web will always be polygonal, determined by the code. The exercise of a skill is always under the dual control (a) of a fixed code of rules (which may be innate or acquired by learning) and (b) of a flexible strategy, guided by environmental pointers -- the 'lie of the land'.

  As the next example let me take, for the sake of contrast, a matrix on the lofty level of verbal thought. There is a parlour game where each contestant must write down on a piece of paper the names of all towns he can think of starting with a given letter -- say, the letter 'L'. Here the code of the matrix is defined by the rule of the game; and the members of the matrix are the names of all towns beginning with 'L' which the participant in question has ever learned, regardless whether at the moment he remembers them or not. The task before him is to fish these names out of his memory. There are various strategies for doing this. One Person will imagine a geographical map, and then scan this imaginary map for towns with 'L', proceeding in a given direction -- say west to east. Another person will repeat sub-vocally the syllables Li, La, Lo, as if striking a tuning fork, hoping that his memory circuits (Lincoln, Lisbon, etc.) will start to 'vibrate' in response. His strategy determines which member of the matrix will be called on to perform, and in which order. In the spider's case the 'members' of the matrix were the various sub-skills which enter into the web-building skill: the operations of secreting the thread, attaching its ends, judging the angles. Again, the order and manner in which these enter into action is determined by strategy, subject to the 'rules of the game' laid down by the web-building code.

  All coherent thinking is equivalent to playing a game according to a set of rules. It may, of course, happen that in the course of the parlour game I have arrived via Lagos in Lisbon, and feel suddenly tempted to dwell on the pleasant memories of an evening spent at the night-club La Cucaracha in that town. But that would be 'not playing the game', and I must regretfully proceed to Leeds. Drifting from one matrix to another characterizes the dream and related states; in the routines of disciplined thinking only one matrix is active at a time.

  In word-association tests the code consists of a single command, for instance 'name opposites'. The subject is then given a stimulus word -- say, 'large' -- and out pops the answer: 'small'. If the code had been 'synonyms', the response would have been 'big' or 'tall', etc. Association tests are artificial simplifications of the thinking process; in actual reasoning the codes consist of more or less complex sets of rules and sub-rules. In mathematical thinking, for instance, there is a great array of special codes, which govern different types of operations; some of these are hierarchically ordered, e.g. addition -- multiplication -- exponential function. Yet the rules of these very complex games can be represented in 'coded' symbols: x+y, or x.y or x^y or x÷y, the sight of which will 'trigger off' the appropriate operation -- as reading a line in a piano score will trigger off a whole series of very complicated finger-movements. Mental skills such as arithmetical operations, motor skills such as piano-playing or touch-typing, tend to become with practice more or less automatized, pre-set routines, which are triggered off by 'coded signals' in the nervous system -- as the trainer's whistle puts a performing animal through its paces.

  This is perhaps the place to explain why I have chosen the ambiguous word 'code' for a key-concept in the present theory. The reason is precisely its nice ambiguity. It signifies on the one hand a set of rules which must be obeyed -- like the Highway Code or Penal Code; and it indicates at the same time that it operates in the nervous system through 'coded signals' -- like the Morse alphabet -- which transmit orders in a kind of compressed 'secret language'. We know that not only the nervous system but all controls in the organism operate in this fashion (starting with the fertilized egg, whose 'genetic code' contains the blue-print of the future individual. But that blue-print in the cell nucleus does not show the microscopic image of a little man; it is 'coded' in a kind of four-letter alphabet, where each letter is represented by a different type of chemical molecule in a long chain; see Book Two, I).*

  Let us return to reasoning skills. Mathematical reasoning is governed by specific rules of the game -- multiplication, differentiation, integration, etc. Verbal reasoning, too, is subject to a variety of specific codes: we can discuss Napoleon's defeat at Waterloo 'in terms of' (a) historic significance, (b) military strategy, (c) the condition of his liver, (d) the constellation of the planets. We can call these 'frames of reference' or 'universes of discourse' or 'associative contexts' -- expressions which I shall frequently use to avoid monotonous repetitions of the word 'matrix'. The jokes in the previous section can all be described as universes of discourse colliding, frames getting entangled, or contexts getting confused. But we must remember that each of these expressions refers to specific patterns of activity which, though flexible, are governed by sets of fixed rules.

  A chess player looking at an empty board with a single bishop on it does not see the board as a uniform mosaic of black and white squares, but as a kind of magnetic field with lines of force indicating the bishops' possible moves: the board has become patterned, as in Fig. 4a; Fig. 4b shows the pattern of the rook.

  When one thinks of 'matrices' and 'codes' it is sometimes helpful to bear these figures in mind. The "matrix" is the pattern before you, representing the ensemble of permissible moves. The "code" which governs the matrix can be put into simple mathematical equations which contain the essence of the pattern in a compressed, 'coded' form; or it can be expressed by the word 'diagonals'. The code is the fixed, invariable factor in a skill or habit; the matrix its variable aspect. The two words do not refer to different entities, they refer to different "aspects" of the same activity. When you sit in front of the chessboard your "code" is the rule of the game determining which moves are permitted, your "matrix" is the total of possible choices before you. Lastly, the choice of the actual move among the variety of permissible moves is a matter of "strategy," guided by the lie of the land -- the 'environment' of other chessmen on the board. We have seen that comic effects are produced by the sudden clash of incompatible matrices: to the experienced chess player a rook moving bishopwise is decidedly 'funny'.

  Consider a pianist playing a set-piece which he has learned by heart. He has incomparably more scope for 'strategy' (tempo, rhythm, phrasing) than the spider spinning its web. A musician transposing a tune into a different key, or improvising variations of it, enjoys even greater freedom; but he too is still bound by the codes of the diatonic or chromatic scale. Matrices vary in flexibility from reflexes and more or less automatized routines which allow but a few strategic choices, to skills of almost unlimited variety; but all coherent thinking and behaviour is subject to some specifiable code of rules to which its character of coherence is due -- even though the code functions partly or entirely on umconscious levels of the mind, as it generally does. A bar-pianist can perform in his sleep or while conversing with the barmaid; he has handed over control to the automatic pilot, as it were.

  Hidden Persuaders

  Everybody can ride a bicycle, but nobody knows how it is done. Not even engineers and bicycle manufacturers know the formula for the correct method of counteracting the tendency to fall by turning the handlebars so that 'for a given angle of unbalance the curvature of each winding is inversely proportional to the square of the speed at which the cyclist is proceeding'. [6] The cyclist obeys a code of rules which is specifiable,
but which he cannot specify; he could write on his number-plate Pascal's motto: Le coeur a ses raisons que la raison ne connaît point. Or, to put it in a more abstract way:

  The controls of a skilled activity generally function below the level of consciousness on which that activity takes place. The code is a hidden persuader.

  This applies not only to our visceral activities and muscular skills, but also to the skill of perceiving the world around us in a coherent and meaningful manner. Hold your left hand six inches, the other twelve inches, away from your eyes; they will look about the same size, although the retinal image of the left is twice the size of the right. Trace the contours of your face with a soapy finger on the bathroom mirror (it is easily done by closing one eye). There is a shock waiting: the image which looked life-size has shrunk to half-size, like a headhunter's trophy. A person walking away does not seem to become a dwarf -- as he should; a black glove looks just as black in the sunlight as in shadow -- though it should not; when a coin is held before the eyes in a tilted position its retinal projection will be a more or less flattened ellipse; yet we see it as a circle, because we know it to be a circle; and it takes some effort to see it actually as a squashed oval shape. Seeing is believing, as the saying goes, but the reverse is also true: knowing is seeing. 'Even the most elementary perceptions', wrote Bartlett, [7] 'have the character of inferential constructions.' But the inferential process, which controls perception, again works unconsciously. Seeing is a skill, part innate, part acquired in early infancy.* The selective codes in this case operate on the input, not on the output. The stimuli impinging on the senses provide only the raw material of our conscious experience -- the 'blooming, buzzing confusion' of William James; before reaching awareness the input is filtered, processed, distorted, interpreted, and reorganized in a series of relay stations at various levels of the nervous system; but the processing itself is not experienced by the person, and the rules of the game according to which the controls work are unknown to him.

  The examples I mentioned refer to the so-called 'visual constancies' which enable us to recognize that the size, brightness, shape of objects remain the same even though their retinal image changes all the time; and to 'make sense' out of our sensations. They are shared by all people with normal vision, and provide the basic structure on which more personal 'frames of perception' can be built. An apple looks different to Picasso and to the greengrocer because their visual matrices are different.

  Let me return once more to verbal thinking. When a person discusses, say, the problem of capital punishment he may do so 'in terms of' social utility or religious morality or psychopathology. Each of these universes of discourse is governed by a complex set of rules, some of which operate on conscious, others on unconscious levels. The latter are axiomatic beliefs and prejudices which are taken for granted and implied in the code. Further implied, hidden in the space between the words, are the rules of grammar and syntax. These have mostly been learned not from textbooks but 'by ear', as a young gypsy learns to fiddle without knowing musical notation. Thus when one is engaged in ordinary conversation, not only do the codes of grammar and syntax, of courtesy and common-or-garden logic function unconsciously, but even if consciously bent on doing so we would find it extremely difficult to define these rules which define our thinking. For doing that we need the services of specialists -- the semanticists and logicians of language. In other words, there is less difference between the routines of thinking and bicycle-riding than our self-esteem would make us believe. Both are governed by implicit codes of which we are only dimly aware, and which we are unable to specify.*

  Habit and Originality

  Without these indispensable codes we would fall off the bicycle, and thought would lose its coherence -- as it does when the codes of normal reasoning are suspended while we dream. On the other hand, thinking which remains confined to a single matrix has its obvious limitations. It is the exercise of a more or less flexible skill, which can perform tasks only of a kind already encountered in past experience; it is not capable of original, creative achievement.

  We learn by assimilating experiences and grouping them into ordered schemata, into stable patterns of unity in variety. They enable us to cope with events and situations by applying the rules of the game appropriate to them. The matrices which pattern our perceptions, thoughts, and activities are condensations of learning into habit. The process starts in infancy and continues to senility; the hierarchy of flexible matrices with fixed codes -- from those which govern the breathing of his cells, to those which determine the pattern of his signature, constitute that creature of many-layered habits whom we call John Brown. When the Duke of Wellington was asked whether he agreed that habit was man's second nature he exclaimed: 'Second nature? It's ten times nature!'

  Habits have varying degrees of flexibility; if often repeated under unchanging conditions, in a monotonous environment, they tend to become rigid and automarized. But even an elastic strait-jacket is still a strait-jacket if the patient has no possibility of getting out of it. Behaviourism, the dominant school in contemporary psychology, is inclined to take a view of man which reduces him to the station of that patient, and the human condition to that of a conditioned automaton. I believe that view to be depressingly true up to a point. The argument of this book starts at the point where, I believe, it ceases to be true.

  There are two ways of escaping our more or less automatized routines of thinking and behaving. The first, of course, is the plunge into dreaming or dream-like states, when the codes of rational thinking are suspended. The other way is also an escape -- from boredom, stagnation, intellectual predicaments, and emotional frustration -- but an escape in the opposite direction; it is signalled by the spontaneous flash of insight which shows a familiar situation or event in a new light, and elicits a new response to it. The bisociative act connects previously unconnected matrices of experience; it makes us 'understand what it is to be awake, to be living on several planes at once' (to quote T. S. Eliot, somewhat out of context).

  The first way of escape is a regression to earlier, more primitive levels of ideation, exemplified in the language of the dream; the second an ascent to a new, more complex level of mental evolution. Though seemingly opposed, the two processes will turn out to he intimately related.

  Man and Machine

  When two independent matrices of perception or reasoning interact with each other the result (as I hope to show) is either a collision ending in laughter, or their fusion in a new intellectual synthesis, or their confrontation in an aesthetic experience. The bisociative patterns found in any domain of creative activity are tri-valent: that is to say, the same pair of matrices can produce comic, tragic, or intellectually challenging effects.

  Let me take as a first example 'man' and 'machine'. A favourite trick of the coarser type of humour is to exploit the contrast between these two frames of reference (or between the related pair 'mind' and 'matter'). The dignified schoolmaster lowering himself into a rickety chair and crashing to the floor is perceived simultaneously in two incompatible contexts: authority is debunked by gravity. The savage, wistfully addressing the carved totem figure -- 'Don't be so proud, I know you from a plum-tree' -- expresses the same idea: hubris of mind, earthy materiality of body. The variations on this theme are inexhaustible: the person slipping on a banana skin; the sergeant-major attacked by diarrhoea; Hamlet getting the hiccoughs; soldiers marching like automata; the pedant behaving like a mechanical robot; the absent-minded don boiling his watch while clutching the egg, like a machine obeying the wrong switch. Fate keeps playing practical jokes to deflate the victim's dignity, intellect, or conceit by demonstrating his dependence on coarse bodily functions and physical laws -- by degrading him to an automaton. The same purpose is served by the reverse technique of making artefacts behave like humans: Punch and Judy, Jack-in-the-Box, gadgets playing tricks on their masters, hats in a gust of wind escaping the pursuer as if with calculated malice.

  In Henri
Bergson's book on the problem of laughter, this dualism of subtle mind and inert matter ('the mechanical encrusted on the living') is made to serve as an explanation of all forms of the comic; whereas in the present theory it applies to only one variant of it among many others. Surprisingly, Bergson failed to see that each of the examples just mentioned can be convened from a comic into a tragic or purely intellectual experience, based on the same logical pattern -- i.e. on the same pair of bisociated matrices -- by a simple change of emotional climate. The fat man slipping and crashing on the icy pavement will be either a comic or a tragic figure according to whether the spectator's attitude is dominated by malice or pity: a callous schoolboy will laugh at the spectade, a sentimental old lady may be inclined to weep. But in between these two there is the emotionally balanced attitude of the physician who happens to pass the scene of the mishap, who may feel both amusement and compassion, but whose primary concern is to find out the nature of the injury. Thus the victim of the crash may be seated in any of the three panels of the triptych. Don Quixote gradually changes from a comic into a puzzling figure if, instead of relishing his delusions with arrogant condescension, I become interested in their psychological causes; and he changes into a tragic figure as detached curiosity turns into sympathetic identification -- as I recognize in the sad knight my brother-in-arms in the fight against windmills. The stock characters in the farce -- the cuckold, the miser, the stutterer, the hunchback, the foreigner -- appear as comic, intellectually challenging, or tragic figures according to the different emotional attitudes which they arouse in spectators of different mental age, culture, or mood.