13. The Genesis of Mind

The brain puzzle

“Organic nature grew out of dead nature; living nature produced a form capable of thought. First, we had matter, incapable of thought; out of which developed thinking matter, man. If this is the case—and we know it is, from natural science—it is plain that matter is the mother of mind; mind is not the mother of matter. Children are never older than their parents. 'Mind' comes later, and we must therefore consider it the offspring, and not the parent … matter existed before the appearance of a thinking human; the earth existed long before the appearance of any kind of 'mind' on its surface. In other words, matter exists objectively, independently of 'mind'. But the psychic phenomena, the so-called 'mind', never and nowhere exists without matter, were never independent of matter. Thought does not exist without a brain; desires are impossible unless there is a desiring organism… In other words: psychic phenomena, the phenomena of consciousness, are simply a property of matter organised in a certain manner, a 'function' of such matter.” (Nikolai Bukharin)

“The interpretation of brain mechanisms represents one of the last remaining biological mysteries, the last refuge of shadowy mysticism and dubious religious philosophy.” (Steven Rose)

For centuries, as we have seen, the central issue of philosophy was the question of the relation between thought and being. Now at last the great strides forward made by science are beginning to shed light on the real nature of the mind and how it works. These advances provide striking confirmation of the materialist outlook. This is particularly the case in relation to the controversies over the brain and neurobiology. The last hiding place of idealism is under attack, which does not prevent the idealists from staging a stubborn rearguard action, as the following quotation shows:

“When it became impossible to investigate this non-material element of creation many dismissed it. They came to think that only matter was real. And so our deepest thoughts were reduced to nothing but the products of brain cells working according to the laws of chemistry…We may study the electrical brain responses that accompany thought, but we cannot reduce Plato to nerve pulses, or Aristotle to alpha-waves…Descriptions of physical movements will never reveal their meaning. Biology can only examine the interlocking world of neurons and synapses.” (Blackmore and Page) ⁵¹

What we call “mind” is just the mode of existence of the brain. This is an immensely complicated phenomenon, the product of many millions of years of evolution. The difficulty in analysing the complex processes that occur within the brain and nervous system, and the equally complex interrelations between mental processes and the environment, has meant that a proper understanding of the nature of thought has been delayed for centuries. This has enabled idealists and theologians to speculate on the allegedly mystical nature of the “soul”, conceived as a non-material substance which deigned to take up temporary residence in the body. The advances of modern neurobiology mean that the idealists are finally being driven from their ultimate refuge. As we begin to unlock the secrets of the brain and nervous system, it becomes progressively easier to explain the mind, without recourse to supernatural agents, as the sum total of brain activity.

In the words of neurobiologist Steven Rose, mind and consciousness are:

“the inevitable consequence of the evolution of particular brain structures which developed in a series of evolutionary changes in the pathway of humanity's emergence…consciousness is a consequence of the evolution of a particular level of complexity and degree of interaction among the nerve cells (neurons) of the cerebral cortex, while the form it takes is profoundly modified for each individual brain by its development in relationship with the environment.” ⁵²

The mind—a machine?

The conceptions of the human brain have changed considerably over the past 300 years, since the birth of modern science and the emergence of capitalist society. The way in which the brain has been perceived has historically been coloured by the existing religious and philosophical prejudices. For the Church, the mind was “God's house”. The mechanistic materialism of the 18th century regarded it as a clockwork machine. More recently, it has been described as an improbable sum of probabilistic events. In mediaeval times, when the Catholic ideology dominated everything, the soul was said to permeate all portions of the body; brain, body, mind or matter were indistinguishable. With the appearance of Copernicus, Galileo and finally Newton and Descartes, with its views of mechanical materialism, there was a shift in this viewpoint.

For Descartes the world was machine-like, and living organisms merely particular types of clockwork or hydraulic machines. It is this Cartesian machine image which has come to dominate science and to act as the fundamental metaphor legitimating a particular world view, which takes the machine as a model for the living organism and not the reverse. Bodies are indissoluble wholes that lose their essential characteristics when they are taken to pieces. Machines, on the contrary, can be dismantled to be understood and then put back together. Each part serves a separate and analysable function, and the whole operates in a regular manner that can be described by the operation of its separate parts impinging on each other.

At each stage, the image of the brain has faithfully reflected the limitations of the science of the period. The mechanistic world-outlook of the 18th century reflected the fact that the most advanced science of the day was mechanics. Had the great Newton not explained the entire universe in terms of the laws of mechanics? Why then should the human body and mind work in any other way? Descartes accepted this point of view when he described the human body as a kind of automaton. But since Descartes was a devout Catholic, he could not bring himself to accept that the immortal soul could be part of this machine. It had to be something entirely separate, situated in a special area of the brain, the so-called pineal gland. From this obscure corner of the brain, the Spirit took up temporary residence in the body, and gave life to the machine. Steven Rose presents this as the source of the:

“inevitable but fatal disjunction of Western scientific thought, the dogma known in Descartes' case and that of his successors as 'dualism'; a dogma which, as we shall see, is the inevitable consequences of any sort of reductionist materialism which does not in the end wish to accept that humans are 'nothing but' the motion of their molecules. Dualism was a solution to the paradox of mechanism which would enable religion and reductionist science to stave off for another two centuries their inevitable major contest for ideological supremacy. It was a solution which was compatible with the capitalist order of the day because in weekday affairs it enabled humans to be treated as mere physical mechanisms, objectified and capable of exploitation without contradiction, while on Sundays ideological control could be reinforced by the assertion of the immortality and free will of an unconstrained incorporeal spirit unaffected by the traumas of the workday world to which its body has been subjected.” ⁵³

In the 18th and 19th centuries, the conception of the mind being the “ghost in the machine” changed. With the advent of electricity, the brain and nervous system were perceived as an electrical maze. At the turn of the century, the telephone exchange analogy emerges, where the brain processes messages from different organs. With the era of mass production came the model of business organisation, as typified in this quote from a child's encyclopaedia:

“Imagine your brain as the executive branch of big business. It is divided, as you see here, into many departments. Seated at the big desk in the headquarters office is the General Manager—your conscious self—with telephone lines running to all departments. Around you are your chief assistants—the Superintendents of Incoming Messages, such as Vision, Taste, Smell, Hearing, and Feeling (the last two hidden behind the central offices). Nearby also are the Superintendents of Outgoing Messages which control Speech and the movement of Arms, Legs, and all other parts of the body. Of course, only the most important messages ever reach your office. Routine tasks such as running the heart, lungs, and stomach, or supervising the minor details of muscular work are carried out by the Managers of Automatic Actions in the Medulla Oblongata and the Manager of Reflex Actions in the Cerebellum. All other departments form what the scientists call Cerebrum.”

With the advent of the computer, which can carry out staggering calculations, the parallel with the brain became inevitable. The very way computers stored information was called memory. More and more powerful computers were built. How close could a computer get to the human brain? Eventually, science fiction brought us the Terminator films, where computers had surpassed human intelligence and fought to take over the world. Yet as Steven Rose explains:

“Brains do not work with information in the computer sense, but with meaning. And meaning is a historically and developmentally shaped process, expressed by individuals in interaction with their natural and social environment. Indeed, one of the problems of studying memory is precisely that it is a dialectical phenomenon. Because each time we remember, we in some senses do work on and transform our memories; they are not simply being called up from store and, once consulted, replaced unmodified. Our memories are recreated each time we remember.” ⁵⁴

What is the brain?

The human brain is the highest point attained by evolution of matter. Physically it weighs about 1.5 kilograms, which is heavier than most human organs. Its surface is wrinkled like a walnut and has a colour and consistence resembling cold porridge. It is, however, extremely complex biologically. It contains a vast number of cells (neurons), possibly numbering 100 billion in total. But even this is dwarfed when we discover that each neuron is embedded in a mass of smaller cells called glia, which serves to support the neurons.

The brain is largely composed of the cerebrum, which is divided into two equal parts. The surface area is known as the cortex. The size of the cortex distinguishes humans from all other organisms. The cerebrum is split into regions or lobes, which correspond roughly to particular body functions and in processing sensory information. Behind the cerebrum lies the cerebellum, which supervises all the tiny muscular movements of the body. Below these parts is a thick stalk or brain stem, which is the continuation of the spinal cord. This carries the nerve fibres from the brain through the spinal cord and throughout the body's nervous system, bringing everything into communication with the brain.

The increased brain size, which decisively sets humans apart from other animals, is mainly accounted for by the enlargement of the thin outer layer of nerve cells known as the neocortex. However, this expansion did not take place uniformly. The frontal lobes, associated with planning and foresight, expanded much more than the rest. The same is true of the cerebellum, at the rear part of the skull, which is associated with the ability to acquire automatic skills, a host of everyday actions which we perform without thinking, such as riding a bike, changing gear while driving or doing up pyjama buttons.

The brain itself contains a circulatory system that brings nutrients to regions distant from a blood supply. It receives a large proportion of blood, which carries vital oxygen and glucose. Although the adult brain makes up only 2 per cent of body weight, its oxygen consumption is 20 per cent of the total—and as much as 50 per cent in an infant. Twenty per cent of the body's glucose consumption occurs in the brain. Fully one fifth of the blood pumped by the heart passes through the brain. The nerves transmit information electrically. The signal that passes down a nerve does so as a wave of electricity; a pulse which passes from the cell body to the end of the nerve fibre. So the language of the brain is composed of electrical impulses, not only the amount but the frequency. “The information upon which such predictions are based,” writes Rose, “depends on the arrival of data at the body surface in terms of light and sound of varying wavelengths and intensities, fluctuations in temperature, pressure on particular points of the skin, concentration of certain chemical substances which are detected by nose or tongue. Within the body this data is transformed into a series of electrical signals passing along particular nerves to the central brain regions where the signals interact with one another producing certain types of response.”

The neuron is composed of a whole number of properties (dendrites, cell body, axon, synapses), which carry out this relay of information (messages arrive at the synapses from the axon). In other words, the neuron is the unit of the brain system. Thousands of motor neurons are involved in any coordinated muscular action. More complex actions will involve millions—though even a million represents only about 0.01 per cent of the total available in the human cortex. But the brain cannot be understood as an assemblage of separate parts. While analysis of the detailed make up of the brain is vital, Rose explains it can only go so far.

“There are many levels at which one can describe the behaviour of the brain. One can describe the quantum structure of atoms, or the molecular properties of the chemicals which compose it; the electron-micrographic appearance of the individual cells within it; the behaviour of its neurons as an interacting system; the evolutionary or developmental history of these neurons as a changing pattern in time; the behavioural response of the individual human whose brain is under discussion; the familial or social environment of that human, and so on.” ⁵⁵

In order to understand the brain, it is necessary to grasp the complex dialectical interrelations of all its parts. It is necessary to bring together a whole host of sciences: ethology, psychology, physiology, pharmacology, biochemistry, molecular biology, and even cybernetics and mathematics.

Evolution of the brain

In ancient mythology, the goddess Minerva sprang fully armed from the head of Jupiter. The brain was not so fortunate. Far from being created in a single instant, it evolved into its present complex system over a period of millions of years. It came into existence at quite a primitive level of evolution. Single celled organisms show certain behaviour patterns (e.g. movement towards light or nutrients). With the advent of multi-cellular life, a sharp division takes place between animal and plant life. While possessing internal signalling devices that enable plants to “communicate”, plant evolution turned away from the evolution of nerves and brain. The movement in the animal kingdom required rapid communication between cells in different parts of the body.

The simplest organisms are self sufficient, possessing all their requirements within a single cell. Communication between one part of the cell and another is relatively simple. On the other hand, multi-cellular organisms are qualitatively different and permit the development of specialisation between cells. Certain cells can deal primarily with digestion, others providing a protective layer, and others circulation, etc. Chemical signalling (hormones) exists in the most primitive multicellular organisms. Even at such a primitive level specialised cells can be found. It is a step towards a nervous system. The more complex organisms, such as flatworms have developed a nervous system, where the neurons are clustered together into a ganglion. It has been established that the ganglion is the evolutionary link between nerves and the brain. These clumps of nerve cells occur in insects, crustaceans and molluscs.

The development of a head and the location of eye spots and mouth are an advantage in receiving information about the direction in which the animal is moving. In conformity with this development a group of ganglia are clustered in the head of a flatworm. It represents the evolution of the brain—despite its primitive form. The flatworm also exhibits learning—a key property of the developed brain. It represents a revolutionary leap forward in evolutionary terms.

American neuroscientists have found that the basic cellular mechanisms for the formation of memory in humans are also present in snails. Professor Eric Kandel of Columbia University studied the learning and memory of a marine snail called Aplysia californica, and found that it exhibited some basic features found in humans. The difference is that, while the human brain has some 100 billion nerve cells, Aplysia only has a few thousand, and they are large. The fact that we share these mechanisms with a marine snail is a sufficient answer to the stubborn attempts of idealists to present humankind as some kind of unique creation, separate and apart from other animals. For almost every function of the brain depends in some way upon memory. No divine intervention is required to explain this phenomenon. Natural processes tend to be very conservative. Having hit upon an adaptation which proves useful for performing certain functions, it is constantly replicated throughout evolution, enlarged and improved upon to the degree that this bestows an evolutionary advantage.

Evolution has introduced many innovations in the brains of animals, especially the higher primates and humans with their very large brains. Whereas Aplysia can “remember” something for several weeks, its memory only involves a level of mental activity known as habit in humans. Such a memory is involved in, say, remembering how to swim. Research into brain-damaged people suggests that the faculty of remembering facts and habit are stored separately in the brain. A person can lose his memory for facts, but still ride a bicycle. The memories that fill a human mind are, of course, infinitely more complex than the processes that go on in the nervous system of a snail.

The continued enlargement of the brain required a drastic change in animal evolution. The nervous system of arthropods or molluscs cannot develop further as a result of a fundamental design problem. The nerve cells are arranged in a ring around the gut, and if expanded would increasingly restrict the gut—a limit sharply revealed in the spider, where the gut is so narrowed by its nerve ring that it can only digest its food as a thin liquid. Insects cannot grow beyond a certain size because their structures would break under their own weight. The brain size has reached its physical limits. Giant insects in horror movies are confined to the realms of science fiction.

The further development of the brain requires the separation of the nerves from the gut. The emergence of vertebrate fish provides the model for the subsequent development of the spinal cord and brain. The skull cavity can house an enlarged brain and the nerves run from the brain through the backbone down the spinal cord. From the eye pits developed an image-forming eye, which could present optical patterns to the nervous system. The emergence of amphibians and reptiles on land saw the great development of the fore-brain region which takes place at the expense of the optic lobes.

Harry Jerison of the University of California developed the idea of the correlation of brain size to body size, and tracked its evolutionary development. He discovered reptiles were small-brained 300 million years ago and remain so today. His graph of reptilian brain size against body size produced a straight line, which includes the dinosaurs. However, the evolution of the early mammals some 200 million years ago marked a leap in relative brain size. These small nocturnal animals were four or five times brainier than the average reptile. This was largely due to the development of the cerebral cortex, which is unique to mammals. This remained the same relative size for some 100 million years. Then, some 65 million years ago, it developed rapidly. According to Roger Lewin, within 30 million years brain development “had increased four to fivefold, with the biggest increases coinciding with the evolution of ungulates (hoofed mammals), carnivores and primates.” ( New Scientist, 5th December, 1992.)

As monkeys, apes and humans evolved, brain size became much bigger. Taking body size into account, monkey's brains are two to three times the average for modern mammals, whereas the human brain is about six times the size. The development of the brain was not of a continuous gradual development but one of fits, starts, and leaps. “Though this broad-brush picture misses important details, the main message is clear enough”, says Roger Lewin, “the brain's history involves long periods of constancy punctuated by bursts of change.”

In under three million years—an evolutionary leap—the brain tripled in relative size, producing a cortex that accounts for 70-80 per cent of brain volume. The first bipedal hominid species evolved somewhere between 10 and seven million years ago. However, their brains were relative small, on a par with the ape. Then, about 2.6 million years ago, a rapid expansion took place with the emergence of Homo. “A leap in the evolution of the ancestors of modern humans took place,” says geologist Mark Maslin of Kiel University. “What evidence there is,” explains Lewin, “suggests that brain expansion began some 2.5 million years ago, a period coinciding with the first appearance of stone tools.” With labour, as Engels explained, came the expansion of the brain and the development of speech. Primitive animal communication gave way to language—a qualitative advance. This must have also depended upon the development of vocal cords. The human brain is capable of making abstractions and generalisations beyond that of the chimpanzee, to which we are closely related.

With the increase in brain size came the increase in complexity and the reorganisation of neural circuitry. The main beneficiary is the front section of the cortex, the prefrontal zone, which is about six times the size of that in apes. Because of its size, this zone can project more fibres to the midbrain, displacing connections there from other brain regions. “This may be significant for the evolution of language”, says Terrence Deacon of Harvard University, who notes that the prefrontal zone is home to certain human speech centres. Rose observes that for humans, this reality of consciousness is revealed in self-awareness and though:

“With the emergence of consciousness, a qualitative evolutionary leap forward has occurred, making for the critical distinction between humans and other species, so that humans have become vastly more varied and subject to complex interactions than is possible in other organisms. The emergence of consciousness has qualitatively changed the mode of human existence; with it, a new order of complexity, a higher order of hierarchical organisation, becomes apparent. But because we have defined consciousness not as a static form but as a process involving interaction between individual and environment, we can see how, as human relationships have become transformed during the evolution of human society, so human consciousness too has been transformed. Our cranial capacity or cell number may not be so different from the early Homo sapiens, but our environments—our forms of society—are very different and hence so too is our consciousness—which also means that so too are our brain states.” ⁵⁶

Importance of speech

The impact of speech—especially the development of “inner speech”—on our brain development is of decisive importance. It is not a new idea, but was known to the ancient Greeks and the philosophers of the 17th century, particularly Thomas Hobbes. In The Descent of Man, Charles Darwin explained: “A long and complex train of thought can no more be carried on without the aid of words, whether spoken or silent, than a long calculation without the use of figures of algebra.” In the 1930s the Soviet psychologist Lev Vygotsky attempted to reestablish the whole of psychology on this basis.

Using examples of child behaviour, he explained why children spend a lot of time talking aloud to themselves. They are rehearsing the habits of planning that they would later internalise as inner speech. Vygotsky showed that this inner speech underpinned the human ability to recollect and recall memories. The human mind is dominated by an inner world of thoughts, stimulated by our sensations, which is capable of generalisation and perspective. Animals also have memories, but they seem to be locked into the present, reflecting the immediate environment. The development of human inner speech allows humans to recall and develop ideas. In other words, inner speech played a key role in the evolution of the human mind.

Although Vygotsky's early death cut short his work, his ideas have been taken up and expanded, with an important input from anthropology, sociology, linguistics and educational psychology. In the past, memory was examined as a unitary biological system, containing short and long-term memory. It could be examined neuro-physiologically, biochemically and anatomically. But today a more dialectical approach, involving other sciences, is being pioneered as argued by Rose:

“In this reductionist approach it follows that the proper task of the sciences of the organism is to collapse the individual's behaviour into particular molecular configurations; while the study of populations of organisms comes down to the search for DNA strands which code for reciprocal or selfish altruism. Paradigm cases of this approach over the last decade have been the attempts to purify RNA, protein, or peptide molecules that are produced by learning and which 'code' for specific memories; or the molecular biologist's search for an organism with a 'simple' nervous system which can be mapped by serial electron microscope sections and in which the different wiring diagrams associated with different behavioural mutations can be identified.” ⁵⁷

Rose concludes that “the paradoxes that this type of reductionism gets itself into are probably more vicious than those of the systems modellers. They have been apparent, of course, since Descartes, whose reduction of the organism to an animal machine powered by hydraulics had to be reconciled, for the human, with a free-willed soul in the pineal gland. As then, so today, mechanistic reductionism forces itself into sheer idealism before it is through.”

In the brain's evolution few parts are totally discarded. As new structures develop, the old ones are reduced in importance and size. With the development of the brain comes the increased capacity to learn. The transformation from ape to man was originally assumed to have begun with brain development. The size of an ape's brain (by volume) ranges from 400 to 600 cubic centimetres; the human brain is 1,200 to 1,500 ccs. It was believed the “missing link” would be essentially ape-like, but with a larger brain. Again it was considered that an enlarged brain preceded upright posture.

This first brain theory was decisively challenged by Engels as an extension of the false idealist view of history. The erect posture in walking was the decisive step in the transition from ape to man. It was their bipedal nature that freed their hands, which lead later to the expansion of the brain. “First comes labour,” says Engels, “after it and then side by side with it, articulate speech—these were the two most essential stimuli under the influence of which the brain of the ape gradually changed into that of man.” ⁵⁸ Subsequent discovery of fossilised remains confirmed Engels's view:

“The confirmation was complete beyond all scientific doubt. The African creatures being unearthed had brains no larger than those of apes. They had walked and run like humans. The foot differed little from that of modern man, and the hand was halfway to human conformation.” ⁵⁹

Despite the growing evidence supporting Engels' views on human origins, the conception of brain-first development is still alive and kicking today. In a recent book entitled The Runaway Brain, The Evolution of Human Uniqueness, the author, Christopher Wills states:

“We know that at the same time as our ancestors' brains were growing larger, their posture was becoming more upright, fine motor skills were developing, and vocal signals were graduating into speech.” ⁶⁰

Man becomes increasingly conscious of his environment and himself. Unlike other animals, humans can generalise their experience. Whereas animals are dominated by their environment, humans change their environment to suit their needs. Science has confirmed Engels' statement that “Our consciousness and thinking, however suprasensuous they may seem, are the product of a material, bodily organ, the brain. Matter is not a product of mind, but mind itself is merely the highest product of matter. This is, of course, pure materialism.” ⁶¹ As the brain develops, so does the capacity to learn and generalise. Important information is stored in the brain, probably in many different parts of the system. This information is not erased as the molecules in the brain are renewed. Within fourteen days, 90 per cent of the brain's proteins are broken down and renewed by identical molecules. Nor is there any reason to believe that the brain has stopped evolving. Its capacity remains infinite. The development of classless society will see a new leap forward in mankind's understanding. For instance, the advances of genetic engineering are only in their infancy. Science opens up enormous opportunities and challenges. The brain and human intelligence will evolve to meet these future challenges. But for every problem solved, many more questions will be raised, in a never-ending spiralling of development.

Language and thought of the child

There appears to be a certain analogy between the development of human thought in general and the development of the language and thought of the individual human being through childhood and adolescence to adulthood.

This point was made by Engels in The Part Played by Labour in the Transition of Ape to Man:

“For, just as the developmental history of the human embryo in the mother's womb is only an abbreviated repetition of the history, extending over millions of years, of the bodily evolution of our animal ancestors, beginning from the worm, so the mental development of the human child is only a still more abbreviated repetition of the intellectual development of these same ancestors, at least of the later ones.” ⁶²

The study of the development from embryo to adult is called ontogeny, whereas the study of evolutionary relationships between species is called phylogeny. Both are strangely linked together, but not as a crude mirror image. For instance, during its development in the womb, the human embryo resembles a fish, an amphibian, a mammal, and appears to pass through phases which recall the stages of animal evolution. All humans are alike in many respects, particularly the substances and structures of the brain. Chemically, anatomically and physiologically there is amazingly little variation. At conception, the fertilised ovum develops into two hollow balls of cells. The first recognised development takes place within eighteen days, as thickening where the balls touch become the neural groove. The forward part enlarges, later to develop into a brain. Other differentiation takes place which will become the eyes, nose and ears. The blood circulation and nervous systems are the first to function in embryo life, with the heartbeat commencing in the third week of conception.

The neural groove becomes a channel and then a tube. In time it will be transformed into the spinal cord. At the head end, swellings appear in the tube to form the forebrain, midbrain and hindbrain. Everything is set for the rapid development of the central nervous system. There is a qualitative leap in the rate of cell division approximating the final cellular structure. By the time the embryo is 13 mm long, the brain has developed into the five-vesicle brain. The stalks that form the optic nerves and eyes emerge. By the end of the third month, the cerebral cortex and cerebellum can be identified, as well as the thalamus and hypothalamus. With the fifth month the wrinkled cortex begins to take shape. All the essentials are developed by the ninth month, although further development will take place after birth. Even then, the weight of the brain is only about 350 grams, compared with 1,300 to 1,500 grams of an adult. It will be 50 per cent of its adult weight at six months, 60 per cent at a year, and 90 per cent at six years. By the age of ten, it would be 95 per cent of its adult weight. The rapid growth of the brain is reflected in the size of the head. The size of a baby's head is large for its body compared to an adult. The brain of a newborn baby is closer than any other organ to its adult state of development. At birth the brain is 10 per cent of the entire body weight compared to only 2 per cent in the adult.

The physical structures of the brain (its biochemistry, cellular architecture and electrical circuitry) are modified by the effects of the brain's response to the environment. Ideas and memories are encoded in the brain in terms of complex changes in the neural system. Thus, all the processes of the brain interact, to give rise to the unique phenomenon of consciousness—matter aware of itself. For Canadian psychologist Donald Hebb, the key lies in the synaptic junctions between two nerve cells, which remains the basis of today's ideas. Particular sets of circuitry and firing patterns between the synapses may encode the memory, but it will not necessarily be localised to a single network of the brain. It can be encoded in both the hemispheres and many times over. The entire scope of the individual's environment, especially in the early years of development, continuously leaves unique impressions on the brain processes and behaviour. “A variety of the most subtle changes in environment, especially during childhood,” says Rose, “can produce long-lasting changes in its chemistry and function.”

Without this dialectical interaction between brain and environment, then the individual's development would simply be prescribed by the genetic code. The behaviour of individuals would be precoded and predictable from the beginning. However, the environment plays a decisive role in development. A changed set of circumstances can bring about a remarkable change in the individual.

Eyes, hand and brain

The development of the language and thought of the child was first subjected to a rigorous analysis in the pioneering work of the Swiss epistemologist Jean Piaget. Some aspects of his theories have been questioned, especially the lack of flexibility with which he interpreted the way children move from one to another of his stages. Nevertheless, this was pioneering work, in a field that had been virtually ignored, and many of his theories retain considerable validity. Piaget was the first one to give an idea of the dialectical process of the development from birth, through childhood to adolescence, as Hegel was the first to provide a systematic exposition of dialectical thinking in general. The defects of both systems should not be allowed to obscure the positive content of their work. Although Piaget's stages are undoubtedly rather schematic, and his research methods open to question, they nevertheless retain value as a general over-view of early human development.

Piaget's theories were a reaction against the views of the behaviourists, whose leading representative, American psychologist Burrhus F. Skinner, was particularly influential in the 1960s in the USA. The behaviourist approach is completely mechanistic, based on a linear pattern of cumulative development. According to this, children learn most efficiently when they are subjected to a linear programme of material devised by expert teachers and curriculum planners. Skinner's educational theories fit in very well with the capitalist mentality. Children will only learn, according to this theory, if they are rewarded for doing so, just as a worker who gets extra pay for overtime.

The behaviourists adopted a typically mechanical position on the development of language. Noam Chomsky pointed out that Skinner adequately described how a baby learned the first few words (mainly nouns), but he did not however explain how these were put together. Language is not just a string of words. It is precisely the combination of the words in a certain dynamic relationship that makes language such a rich, effective, flexible and complex instrument. Here, most decidedly, the whole is greater than the sum of the parts. It is really an incredible feat for a child of two to learn the rules of grammar, as any adult who has tried to learn a foreign language will agree.

Compared to this crude and mechanistic dogma, Piaget's theories represented a great step forward. Piaget explained that learning comes naturally to children. It is the job of the teacher to bring out those tendencies which are already present in all children. Moreover, Piaget correctly pointed out that the process of learning is not a straight line, but is punctuated by qualitative breakthroughs. Although Piaget's original stages are open to question, there is no doubt that this dialectical approach, in general, was valid. What was valuable in Piaget's work was that the development of the child was presented as a contradictory process in which each stage was based on the previous one, both overcoming and preserving it. The genetically conditioned base provides the ready-made material, which from the first moment enters into a dialectical interaction with the environment. The newborn baby is not conscious, but driven by deep-rooted biological instincts that urgently demand satisfaction. These powerful animal instincts do not disappear, but remain as an unconscious substratum, underlying our activities.

To use the language of Hegel, what we have here is the transition from being-in-itself to being-for-itself—from potential to actual, from an isolated, helpless, unconscious being, a plaything of natural forces to a conscious human being. The movement towards self-consciousness, as Piaget correctly explained, is a struggle, which passes through different phases. The newborn baby does not clearly distinguish itself from its surroundings. Only slowly does it become aware of the distinction between the self and the external world. “The period from birth to the acquisition of language,” writes Piaget, “is marked by an extraordinary mental development.” Elsewhere, he describes the first 18 months of existence as “a Copernican revolution on a small scale.” ⁶³ The key to this process is the gradual dawning of the realisation of the relation between the subject (self) and the object (reality), which must be understood.

Vygotsky and Piaget

The earliest and best of the critics of Piaget was Vygotsky, the Soviet educationalist who, in the period 1924-34, worked out a consistent alternative to Piaget's ideas. Tragically, Vygotsky's ideas were only published in the Soviet Union after the death of Stalin, and became known in the West in the 1950s and 60s, when they exercised a powerful influence on many, like Jerome Bruner. At the present time, they are widely accepted by educationalists.

Vygotsky was in advance of his time in explaining the important role of gestures in the development of language. This has been revived more recently by psycholinguists unravelling the origins of language. Bruner and others have pointed to the enormous impact of gestures on the later development of language in a child. Whereas Piaget placed more emphasis on the biological aspect of the development of the child, Vygotsky concentrated more on culture, as have people like Bruner. An important part in culture is played by tools, whether they are the sticks and stones of early hominids, or pencils, rubbers and books of today's children.

Recent research has shown that babies are more capable at an earlier stage than Piaget thought. His ideas about very young babies seem to have been overtaken, but much of his research remains valid. Coming from a biological background, it was inevitable that he should place heavy stress on this aspect of the child's development. Vygotsky approached the question from a different point of view, but nevertheless, there are common points. For example, in his study of the early years of childhood, he deals with “nonlinguistic thought” such as Piaget outlined in his account of “sensorimotor activity”, such as using a rake to reach another toy. Alongside this, we notice the incomprehensible sounds of the baby (“baby-talk”). When the two elements combine, there is an explosive development of language. For each new experience, the toddler wants to know the name. While Vygotsky took a different route, the trail was blazed by Piaget:

“The process of growing up is not a linear progression from incompetence to competence: to survive, a newborn baby must be competent at being a newborn baby, not at being a tiny version of the adult it will later become. Development is not just a quantitative process but one in which there are transformations in quality—between suckling and chewing solid food, for instance, or between sensorimotor and cognitive behaviour.” ⁶⁴

Only gradually, over a long period and by a difficult process of adjustment and learning, does the child cease to be a bundle of blind sensations and appetites, a helpless object, and become a conscious, self-directing free agent. It is this painful struggle to pass from the unconscious to the conscious, from utter dependence on the environment to the domination of the environment, which provides the striking parallel between the development of the individual infant and that of the human species. Of course, it would be wrong to imply that the parallel is a precise one. Every analogy holds good only within definite limits. But it is hard to resist the conclusion that in at least some aspects such parallels do, in fact, exist. From lower to higher; from simple to complex; from unconscious to conscious—such features recur constantly in the evolution of life.

The animals depend more than humans upon the senses, and have better hearing, eyesight and sense of smell. It is noticeable that keenness of eyesight reaches a high point in late childhood, and thereafter diminishes. On the other hand, the higher intellectual functions continue to develop through life, and well into old age. To trace the path whereby humans pass from the unconscious to the level of real consciousness is one of the most fascinating and important tasks in science.

At birth, the baby knows only reflexes. But this does not at all signify passivity. From the very first moment of its existence, the baby's relation with its environment is active and practical. It does not think only with its head, but with its whole body. The development of the brain and consciousness is directly related to its practical activity. One of the first reflexes is sucking. Even here the process of learning from experience is present. Piaget points out that the baby suckles better after one or two weeks than at first. Later on comes a process of discrimination, where the child begins to recognise things. Later still, the child begins to draw its first generalisations, not only in thought but in action. It does not only suckle at the breast, but also sucks the air, and then his fingers. The Spanish have a saying: “I don't suck my thumb,” meaning “I'm not stupid.” As a matter of fact, the ability to introduce a thumb into the mouth is quite a difficult task for a baby, which usually appears at about two months, and marks a significant step forward, denoting a certain level of co-ordination of hand and brain.

Immediately after birth the child has difficulty in focusing its attention on particular objects. Gradually, it becomes able to concentrate on specific objects, and anticipates where they are so that it can move its head in order to see them. This development, analysed by Bruner, takes place during the first two or three months, and involves not only the purely visual field, but also activity—the orientation of the eyes, head, and body towards the object of attention. At the same time, the mouth becomes the link between vision and manual movement. Gradually, it begins a process of visually guided reaching-grasping-retrieving, which always concludes by bringing the hand to the mouth.

For the newborn child, the world is first and foremost something to be sucked. Later, it is something to be looked at and listened to, and, when a sufficient level of co-ordination permits it, something to be manipulated. This is not yet what we could call consciousness, but it is the starting-point of consciousness. A very lengthy process of development is needed for these simple elements to become integrated into habits and organised perceptions. Later on, we get systematic thumb-sucking, the turning of the head to the direction of a sound, following a moving object with the eyes (indicating a level of generalisation and anticipation). After five weeks or more, the baby smiles, and recognises some people rather than others, although this cannot be taken to mean that the baby possesses a notion of a person, or even an object. This is the stage of the most elementary sense perception.

In its relations to the objective world, the baby has two possibilities: either to incorporate things (and people) into its activities, and thus to assimilate the material world, or to readjust its subjective wishes and impulses to the external world, i.e., to accommodate to reality. From a very early age, the baby tries to “assimilate” the world to itself, by introducing it into its mouth. Later, it learns to adjust to external reality, gradually begins to distinguish and perceive different objects, and remembers them. It acquires, through experience, the ability to carry out a number of operations, like reaching and grasping. Logical intelligence arises first from concrete operations, from practice, and only much later as abstract deductions.

Piaget identified six clearly defined “stages” in the development of the child. The stage of reflexes or hereditary functions includes primary instinctive tendencies such as nutrition. The need to obtain food is a powerful inborn impulse, controlling the reflexes of the newborn child. This is a common feature which humans share with all animals. The newborn child, lacking the elements of higher thought, is nonetheless a natural materialist, who expresses his firm belief in the existence of the physical world in exactly the same way as all animals—by eating it. It takes a great deal of intellectual refinement before clever philosophers succeed in convincing people that we cannot really say whether the material world is out there or not. This supposedly complicated and profound philosophical question is in fact resolved by a baby in the only possible way— through practice.

From the age of two, the child enters a period of symbolic thought and preconceptual representation. The child begins to use picture images as symbols to replace the real things. Parallel to this is the development of language. The next stage is conditional representation, recognising other points of reference in the world, and simultaneously is developed coherent language. This is followed by operational thinking from seven to twelve years of age. The child begins to recognise relationships between objects and to deal with more abstract conceptions.

It is precisely practice, and the interaction of inborn, genetically conditioned tendencies, which provide the key to the mental development of the child. Piaget's second stage is that of primary motor habits, accompanied by the first “organised perceptions” and primary “differentiated feelings”. The third stage is that of “sensori-motor intelligence” or practice (which is prior to speech). Then comes the phase of “intuitive intelligence” involving spontaneous relations between individuals, especially submission to adults; the phase of “concrete intellectual operations” which includes the development of logic and moral and social feelings (from 7 to 11 or 12 years); and finally, a phase of abstract intellectual operations—the formation of personality and emotional and intellectual integration in adult society (adolescence).

Human progress is closely linked to the development of thought in general, and science and technology in particular. The capacity for rational, abstract thought does not come easily. Even now, the minds of most people rebel against thought that leaves behind the familiar world of the concrete. This ability appears quite late in the mental development of the child. We see this in children's paintings, which depict what the child actually sees, not what they ought to see, according to the laws of perspective, and so on. Logic, ethics, morality, all appear late in the child's intellectual development. In the first period, every action, every movement, every thought, is the product of necessity. The notion of “free will” has nothing whatever to do with the mental activities of the child. Hunger and fatigue lead to desire for food or sleep, even in the youngest baby.

The possession of a capacity for abstract thought, even on the most primitive level, makes the subject master of the most distant events, both in space and time. This is as true for the child as it was for early humans. Our earliest ancestors did not clearly distinguish themselves from other animals or inanimate nature. Indeed, they had not fully emerged from the animal kingdom, and were very much at the mercy of the forces of nature. The elements of self-awareness seem to exist in chimpanzees, our nearest relatives, though not in monkeys. But only in humans does the potential for abstract thought reach its full expression. This is closely related to language, one of the fundamental distinguishing features of humankind.

The neocortex, which makes up 80 per cent of the volume of the human brain, is the part responsible for relations with groups, and is related to thinking in general. There is a close connection between social life, thought and language. The self-centred nature of the newborn baby gradually gives way to a realisation that there is an external world, people and society, with its own laws, demands and restrictions. Quite late on, between three and six months, according to Piaget, the phase of grasping begins, involving first pressure, then manipulation. This is a decisive step, leading to a multiplication of the baby's powers and the formation of new habits. After this, development becomes speeded up. The dialectical nature of the process is indicated by Piaget:

“The point of departure is always a reflex cycle, but a cycle the exercise of which, instead of repeating itself without more ado, incorporates new elements and constitutes with them still wider organised totalities, thanks to progressive differentiations.” Thus the development of the child is not a straight line or a closed circle, but a spiral, where long periods of slow change are interrupted by sudden leaps forward, and each stage involves a qualitative advance.

Piaget's third stage is that of “practical intelligence” or the “sensorimotor stage as such”. The exact nature and delineation of these “stages” is, of course, debatable, but the general thrust remains valid. Intelligence is closely related to the manipulation of objects. The development of the brain is directly linked to the hand. As Piaget says:

“But it is a question of an exclusively practical intelligence, which is applied to the manipulation of objects, and which, in place of words and concepts, only makes use of perceptions and organised movements in schemes of action.” ⁶⁵

From this we see that the basis of all human knowledge is experience, activity and practice. The hands, in particular, play a decisive role.

The emergence of language

Before speech develops as such, the baby makes use of all kinds of signs, eye contact, cries and other body language, to exteriorise its wants. In the same way, it is clear that before the earliest hominids could speak, they must have used other means to signal to one another. The rudiments of such communication exist in other animals, especially the higher primates, but only in humans does speech exist as such. The long struggle of the child to master speech, with its complex underlying patterns and logic, is synonymous with the acquisition of consciousness. A similar road must have been traversed by early humans.

The throat of the human infant, like that of apes and other mammals, is so constructed that the vocal passage is low down. In this way, it is capable of making the kind of cries that animals make, but not articulate speech. The advantage of this is that it can cry and eat at the same time, without choking. Later on, the vocal passage migrates upwards, reflecting a process that actually occurred during the course of evolution. It is unthinkable that human speech would have arisen all at once, without all kinds of transitional forms. This took place over millions of years, in which there were undoubtedly periods of rapid development, as we see in the development of the human infant.

Can thought exist without language? That depends on what is meant by “thought”. The elements of thought exist in animals, especially the higher mammals, which also possess certain means of communication. Among the chimpanzees, the level of communication is quite sophisticated. But in none of these can we speak of either language or thought anything remotely on the human level. The higher develops from the lower, and could not exist without it. Human speech originates in the incoherent sounds of the baby, but it would be foolish to identify the two. In the same way, it is a mistake to try to show that language existed before the human race.

The same is true of thought. To use a stick to get hold of an object that is out of reach is an act of intelligence. But this appears quite late in the development of the child—about 18 months. This involves the use of a tool (a stick) in a coordinated move, in order to realise a preconceived aim. It is a deliberate, planned action. This kind of activity can be seen among apes, and even monkeys. The use of objects found ready to hand—sticks, stones, etc.—as adjuncts to food-gathering activities is well documented. At twelve months, the child has learnt to experiment by throwing an object in different directions to “see what happens”.

This is a repeated purposeful activity, designed to get results. It implies an awareness of cause and effect (if I do this, then that will happen). None of this knowledge is innate. It is learned through experience. It takes the child 12-18 months to grasp the notion of cause and effect. A most powerful piece of knowledge! It must have taken early humans millions of years to learn the same lesson, which is the real basis of all rational thought and purposeful action. All the more absurd that, at a time when our knowledge of nature has reached such dazzling heights, certain scientists and philosophers should wish to drag thought back to what is really a primitive and childish state, by denying the existence of causality.

In the first two years of life, an intellectual revolution takes place, in which the notions of space, causality and time are formed, not, as Kant imagined, out of thin air, but as a direct result of practice and experience of the physical world. All human knowledge, all the categories of thought, including the most abstract ones, are derived from this. This materialist conception is clearly proven by the development of the child. Initially, the infant does not distinguish between reality and itself. But at a certain point, the realisation dawns that what it sees is something outside itself, something which will continue to exist even when it is no longer seen. This is the great breakthrough, the “Copernican revolution” of the intellect. Those philosophers who assert that the material world does not exist, or that this cannot be proven, are, in a literal sense of the word, expressing an infantile idea.

The baby who cries when its mother leaves the room shows that it understands that she has not disappeared just because she is no longer in its field of vision. It cries in the certainty that this action will bring about her return. Up to the first year, the child believes that what is out of sight has, in effect, ceased to exist. By the end of the second year, it already recognises cause and effect. Just as there is no Chinese Wall separating thought from action, so there is no absolute dividing line between the intellectual life of the child and its emotional development. Feelings and thoughts are, in fact, indivisible. They constitute the two complementary aspects of human behaviour. Everyone knows that no great enterprise is achieved without the element of the will. Emotions are a most powerful lever for human action and thought, and play a fundamental role in human development. But at every stage, the intellectual development of the child is inextricably bound up with activity. As intelligent behaviour emerges, emotional states of mind are associated with actions—cheerfulness or sadness are linked with the success or failure of intentional acts.

The emergence of language represents a profound modification in the behaviour and experience of the individual, both from an intellectual and emotional standpoint. It is a qualitative leap. The possession of language creates, to quote Piaget, “the ability to reconstruct his past actions in the form of narration and to anticipate his future actions through verbal representations.” With language, past and future become real for us. We can rise above the restrictions of the present, plan, predict and intervene according to a conscious plan.

Language is a product of social life. Human social activity is unthinkable without language. It must have been present, in one form or another, in the earliest truly human societies, from the very earliest times. Thought itself is a kind of “internal language”. With language comes the possibility of real human social intercourse, the creation of a culture and tradition which can be learned and passed on orally, and later on in writing, as opposed to mere imitation. It also makes possible genuine human relations, where feelings of antipathy, sympathy, love and respect can be expressed in a more coherent, developed way. In embryo, these elements are present from the first six months in the form of imitation. The first words are pronounced, usually isolated nouns. Then the child learns to put two words together. Nouns are gradually connected with verbs and adjectives. Finally, the mastering of grammar and syntax entails extremely complex patterns of logical thought. This is a tremendous qualitative leap for every individual as it was for the species.

Very young children can be said to have a “private” language, which is not language in the real sense, but only sounds which represent experiments and attempts to copy adult speech. Articulate speech grows out of these sounds, but the two must not be confused. Language, by it very nature, is not private, but social. It is inseparable from social life and collective activity, in the first place, co-operation in production, which lies at the basis of all social life from the earliest times. Language represents a colossal leap forward. Once the process started, it would have enormously speeded up the development of consciousness. This can be seen also in the development of the child.

Language represents the beginnings of the socialisation of human activity. Before this, early pre-humans must have communicated by other means: cries, body language and other gestures. Indeed, modern humans continue to do so, particularly in moments of great stress or emotion. But the limitations of this kind of “language” are self-evident. They are hopelessly inadequate to convey more than immediate situations. The level of complexity, abstract thought and planning needed for even the simplest human societies based on co-operative production cannot be expressed by such means. Only through language is it possible to escape from the immediate present, recall the past, and foresee the future. Only though language is it possible to establish a really human form of communication with others, to share one's “inner life” with them. Thus we talk of “dumb animals” as a distinction from humans, the only animals that possess speech.

Socialisation of thought

Through language, the child is initiated into the wealth of human culture. Whereas with other animals, the factor of genetic inheritance is predominant, in human society, the cultural factor is decisive. The human infant has to go through a very long period of “apprenticeship” in which it is completely subordinated to adults, particularly its parents, who, largely by means of language, initiate it into the mysteries of life, society and the world. The child finds itself confronted with a ready-made model to copy and imitate. Later this is expanded to include other adults and children, especially through play. This process of socialisation is not easy or automatic, but it is the basis of all intellectual and moral development. All parents have noticed with amusement how small children will withdraw into a world of their own, and quite happily conduct a “conversation” with themselves for long periods, while playing on their own. The development of the child is intimately linked to the process of breaking away from this primitive state of egocentricity, and relating to others and to external reality in general.

In Piaget's original scheme, the period from two to seven years marks the transition from the simply “practical” (“sensorimotor”) phase of the intelligence, to thought as such. This process is characterised by all kinds of transitional forms between the two. It reveals itself in play, for example. From seven to twelve, games appear with rules, implying common objectives, as opposed to playing with dolls, say, which is highly individual. The logic of primary infancy can be described as intuition, which is still present in adults—what Hegel calls “immediate” thought. At a later stage, well known to parents, the child begins to ask why? This naïve curiosity is the beginning of rational thinking—the child is no longer willing just to take things as they are, but seeks a rational ground for them. It grasps the fact that all things have a cause, and tries to grasp what this is. It is not satisfied with the mere fact that “B” happens to occur after “A”. It wishes to know why it has occurred. Here too the child of between three to seven years of age shows itself to be wiser than some modern philosophers.

Intuition, to which a certain aura of magic and poetry has been traditionally attached, is, in fact, the lowest form of thinking, characteristic of very small children and people on a low level of cultural development. It consists of the immediate impressions provided by the senses, which provoke us to react “spontaneously”, that is, in an unthinking way, to a given circumstance. The rigours of logic and consistent thought do not enter into it. Such intuitions can sometimes be spectacularly successful. In such cases, the apparently spontaneous nature of the “flash of inspiration” provides the illusion of a mysterious insight coming “from within” and divinely inspired. In fact, intuition comes, not from the obscure depths of the soul, but from the interiorisation of experience, which is obtained, not in a scientific way, but in the form of images and the like.

A person with considerable experience of life can frequently arrive at an accurate assessment of a complicated situation on the basis of the scantiest information. Similarly, a hunter can display almost a “sixth sense” about the animals he is tracking. In the case of truly great minds, flashes of inspiration are considered to represent a quality of genius. In all these cases, what appears to be a spontaneous idea is, in fact, the distilled essence of years of experience and reflection. More often, however, mere intuition leads to a highly unsatisfactory, superficial and distorted form of knowledge. In the case of children, “intuition” marks the primitive, immature phase of thought, before they are able to reason, define and judge. It is so inadequate that it is generally regarded as comical by adults, who have long since left this phase behind. In all these cases, it goes without saying that there is nothing mystical involved.

In the first stages of life, the child does not distinguish between itself and its physical environment. Only gradually, as we have seen, does the child begin to distinguish between the subject (“I”) and the object (the physical world). It begins to understand the real relationship between its environment and itself in practice, through manipulation of objects and other physical operations. The primitive unity is broken down, and a confusing multiplicity of sights, sounds and objects emerges. Only later does the child begin to grasp the connections between things. Experiments have shown that the child is consistently more advanced in deeds than in words.

There is no such thing as a “purely intellectual act”. This is particularly clear in the case of small children. It is commonplace to counterpose the heart and the head. This, too, is a false opposition. The emotions play a part in the solution of intellectual problems. Scientists become excited over the solution of the most abstruse equations. Different schools of thought clash heatedly over problems of philosophy, art, and so on. On the other hand, there is no such thing as pure acts of affection. Love, for example, presupposes a high degree of understanding between two people. Both the intellect and the emotions play a role. The one presupposes the other, and they intervene and condition each other, to a greater or lesser degree.

As the degree of socialisation advances and develops, the child becomes more aware of the need for what Piaget calls “inter-personal sentiments”—the emotional relations between people. Here we see that the social bond itself involves contradictory elements of attraction and repulsion. The child learns this first in relation to its parents and family, and then forms close bonds with broader social groups. Feelings of sympathy and antipathy are developed, linked to the socialisation of actions, and the appearance of moral sentiments—good and bad, right and wrong, which mean much more than “I like” or “I dislike”. They are not subjective but objective criteria derived from society.

These powerful bonds are an important part of the evolution of human society, which, from the outset was based on co-operative social production and mutual dependence. Without this, humanity would have never emerged from the animal world. Morality and tradition are learned through language, and passed on from generation to generation. Compared to this, the factor of biological inheritance appears quite secondary, although it remains the raw material from which humanity is constructed.

With the commencement of proper schooling, from about the age of seven, the child begins to develop a strong sense of socialisation and co-operation. This is shown in games with rules—even a game of marbles requires a knowledge and acceptance of quite complicated rules. Like the rules of ethics and the laws of society, they must be accepted by all, in order to be viable. A knowledge of rules and how they are to be applied goes together with a grasp of something as complicated as the grammatical and syntactical structure of language.

Piaget makes the important observation that “all human behaviour is at the same time social and individual.” Here we have a most important example of the unity of opposites. It is entirely false to counterpose thought to being, or individual to society. They are inseparable. In the relationship between subject and object, between the individual and the environment (society) the mediating factor is human practical activity (labour). The communication of thought is language (exteriorised reflection). On the other hand, thought itself is interiorised social intercourse. At seven years of age, the child begins to understand logic, which consists precisely of a system of relations, permitting the coordination of points of view.

In a brilliant passage, Piaget compares this stage with the early stage of Greek philosophy, when the Ionian materialists parted company with mythology, in order to arrive at a rational understanding of the world:

“It is surprising to observe that, among the firsts (new forms of explanation of the uniters) to appear, there are some which present a notable similarity to that given by the Greeks precisely in the epoch of decline of mythological explanations, properly so-called.”

Here we see, in a very striking way, how the forms of thought of each individual child in its early development, provides a rough parallel to the development of human thought in general. In the early stages, there are parallels with primitive animism, where the child thinks that the sun shines, because it was born. Later the child imagines that clouds come from smoke, or air; stones are made of earth, etc. This recalls the early attempts to explain the nature of matter in terms of water, air, and so on. The great significance of this is that it was a naïve attempt to explain the universe in materialist, scientific terms, rather than in terms of religion and magic. The child of seven begins to grasp the notion of time, space, speed, etc. However, this takes time. Contrary to Kant's theory that the notion of time and space are inborn, the child cannot grasp such abstract ideas until they are experimentally demonstrated. Thus, idealism is shown to be false by a study of the processes of developing of human thought itself.

^{51. Blackmore, V. and Page, A. Evolution: the Great Debate, pp. 185-6, our emphasis.↩}

^{52. Rose, S. The Conscious Brain, p. 31.↩}

^{53. Rose, S. Molecules and Minds, p. 23.↩}

^{54. Rose, S. The Making of Memory, p. 91.↩}

^{55. Rose, S. The Conscious Brain, p. 28.↩}

^{56. Rose, S. The Conscious Brain, p. 179.↩}

^{57. Rose, S. Molecules and Mind, pp. 96-7.↩}

^{58. Engels, F. Dialectics of Nature, p. 284.↩}

^{59. Washburn, S. and Moore, R. Ape into Man: A Study of Human Evolution.↩}

^{60. Wills, C. op. cit., p. 8, our emphasis.↩}

^{61. MESW, Vol. 3, p. 348.↩}

^{62. Engels, F. The Dialectics of Nature, p. 241.↩}

^{63. Piaget, J. The Mental Development of the Child, p. 19.↩}

^{64. Rose, S. Leon J. Kamin and Richard Lewontin, Not In Our Genes, p. 96.↩}

^{65. Piaget, J. op. cit., p. 22.↩}