There is something paradoxical about having a final section of a book of this kind (presenting a closely-argued thesis) under the rubric of 'Conclusion'. In any systematic theory (as a matter of history in the development of science, and possibly also in the development of philosophy), the conclusion is the point from which the author has started. Conversely, the Introduction of such a book looks to the past, to the work that has already been done, both by others and by the author himself, and indicates, as the introduction to this book does, the guiding scheme, which there seems no need to recapitulate here. The function of the seven preceding chapters has been an attempt to give solidity to the outline, to bring the reader to see the specific manner in which ideas drawn from widely separated scientific and philosophical disciplines share similarities of underlying structure. Bohm(1) has commented, in a quite different context, that the purpose of a theory is to obtain the essence or unity behind the diversity of phenomena (in his case to bring order into the multitude of elementary physical particles, which can only be accommodated, at present, by increasingly elaborate theoretical constructs resembling the Ptolemaic epicycles). Curiously, the enterprise in this book can be presented in the terms of the theory itself, that it constitutes an attempt to show how a coherent view, a new perception of the elements and relationships in the intellectual 'raw material' provided by the present-day results and speculations of linguistics, psychology, neurology and philosophy, can be arrived at, how new Figures can emerge from the Ground of current thought and theory. As with the familiar voluntary changes in perception demonstrated by the Gestalt psychologists, the book has sought to demonstrate how the whole scientific and philosophical scene changes if one chooses to see a natural orderliness in language rather than the merely arbitrary.

But if this Conclusion is to be thought of rather as a beginning, in what direction should we expect to move? Kant commented that knowledge must not remain a rhapsody but must become a system. There are obviously large gaps in current knowledge and understanding of visual perception, of the neurological co-ordination of action, of the cognitive patterning underlying language and thought - and indeed in the systematic analysis of the familiar phenomena of world languages. These are gaps which it will take many years and much effort to fill and, though the attempt made in this book to relate the structures of language, vision and action, may be criticised as premature because these gaps exist, any general theory is always in a sense premature - it has to reach out ahead of the hard experimental fact. The test of the value of a general theory is whether, whilst preserving what has already been learnt or partial theory has already validated, it suggests new questions to be asked, new directions of research to be followed, a new concreteness in the significance attached to the terms already in use in the different disciplines. Specifically, what difference would this new view of the nature of language make, most narrowly, to the practice of linguistics and, more broadly, to our attitude to language in all its uses, to the understanding of the relation of language, perception and brain function, to our view of the natural basis of social and cultural organisation and, finally, to the philosophical understanding of human nature, the relation of human consciousness and the world?

For linguistics, acceptance of a natural basis for language must mean a radical transformation. There is a growing consensus, amongst those not professionally committed to the particular dogmas of generative grammar (based on concepts of deep structure and specifically linguistic 'competence') that linguistics has reached, if not a dead end, at least a point of crisis. It has been argued, with much force, that contemporary linguistics has gone fundamentally astray, both conceptually and methodologically, and linguists now are faced with the question whether a science of language (of the language process) is possible - or whether anything as variable and intricate could ever be 'tamed' by scientific theories. "One does not make an empirical science out of a discipline merely by wishing or proclaiming it to be so ... and to become truly scientific the "condition is that language loses its singularity, becomes one phenomenon among many ... subject to the same principles of perception, learning and motivation, that are believed to govern all thought and behaviour"(3). The hypothesis of the natural and evolutionary basis of language presented in this book has as an immediate consequence the integration of linguistics with the rest of science, and particularly with biology, neurology and physiology. This consequence closely parallels what Darwin described as an immediate consequence of acceptance of the natural origin of species: "the terms used by naturalists, of affinity, relationship, community of type, paternity, morphology, adaptive characters etc. will cease to be metaphorical and will have a plain signification"(4). The same can be said of many of the traditional and modern terms and concepts in linguistics - the metaphorical 'genetic' relation of languages becomes a genuinely genetic relationship, the forms of words and sentences are seen to reflect real forms of neurological and physiological organisation, the 'deep structure' of syntax is seen to be literally a deep underlying structure of the physical organism as it reflects and models the external world,

But perhaps even more important than the direct impact on linguistics as a science in embryo, is the significance of the new view of language for research into brain function. The Introduction quoted Lashley's view of language as a route towards understanding the physiology of the cerebral cortex, speech as the only window through which the physiologist can view cerebral life. From quite different points of view others have commented that 'the central clue to the understanding of man is not his science but his language' and that 'language is something essential to comprehension, something at the very heart of consciousness'. At present, the neurology of voluntary action, of language and of perception, of thought and consciousness, present difficulties of 'astronomical proportions', and research into each of these has inevitably been treated as a distinct field of study. If one now assumes, on the theory presented here, an underlying functional integration of language, vision and action, then the 'window' into the brain that language affords becomes of vastly greater potential importance. One can begin to see how, neurologically, the correlation of perception, action and speech in the cerebral cortex might, against the background of awareness of the postural schema (the body image) from moment to moment, form the basis for the analogue or model of the world mapped in the brain, which Kenneth Craik(7), some years ago, put forward as a hypothesis. Such a model would serve to allow us to predict the outcome of events and to formulate and execute our own actions, to serve as the basis for all our computations. There is experimental evidence of the direct interaction of vision, speech and action with the postural schema and the brain's model of the external world. An animal that lacks information about the posture and movements of its own body, it has been found, cannot interpret visual information presented to it; human subjects with a disturbed postural model (through brain injury) may be incapable of voluntarily initiating a movement; patients suffering from aphasia 'may be able to name objects presented in their normal environment but not when they are presented in an artificial environment as part of a test'. J.Z. Young remarks that "the brain has many distinct parts but there is increasing evidence that they are interrelated to make one functioning whole"(8) - and the inter-relation of speech, vision and action proposed in this book goes some way towards suggesting, in part at any rate, the form which that integration may take, through the correlation of patterns, sensory and motor, within the cerebral cortex, At the same time, the new view of language may suggest some new directions of exploration for the efforts being made by the practitioners of Artificial Intelligence to decipher the code of the brain by imitating small parts of it. Up to now, theories proposed in linguistics and related fields have been too incomplete and too vaguely stated to be realised in computational terms and only a few tiny fragments of the spectrum of human abilities have begun to be simulated. In this book, an attempt has been made to translate a very broad theory into specific detail and this may well provide some solider grist for the AI mill.

Quine(9), in discussing the relation of word and object, at one point described a river as a process through time. Language, as a naturally based system, can be seen as a river of thought flowing through time - like all human behaviour an expression of interaction between genetic patterning and the environment within which the genes are expressed. Language is stable yet at the same time over long periods it changes progressively and systematically. Evolutionary change to track the environment (using Wilson's(10) terminology in sociobiology) can be long-term (as the genetic composition of a population shifts to a mode better adapted to long-term environmental changes) or medium-term (micro-evolution in inbred small human groups converting cultural practices into selective factors affecting the gene-pool) or fast, short-term. By this last is meant that in so far as the expression of a genetic inheritance is necessarily dependent upon the environment in which the organism is placed, and part of the genetic inheritance, in human beings, consists of potentialities for neurological structuring to match the social environment, as in the case of language, 'evolutionary change ... is going on now from second to second, as a result of the very rapid evolution of afferent neuronal structures, produced by the intake and accumulation of information"(8) (J.Z. Young). The changes in the content of language, the concepts distinguished in the lexicon, the analysis of syntactic relationships ever more precisely and finely, on this view of language, represent real and not merely metaphorical cultural evolution - and one can conclude that in these terms all languages are not at similar stages of development; some are, evolutionarily, more advanced than others (reflecting real neurological differences between the members of different language communities). As an extreme example, one might speculate how difficult or easy it would be to translate nuclear physics or Hegel into a lexically or syntactically primitive language, such as those found among the Australian aborigines. At the same time, besides the rapidity of change in the content of language, there are factors making for stability which are directly analogous with those identified in other evolutionary processes what has been described as 'phylogenetic inertia This in social terms makes its appearance as the force of tradition. The factors which determine inertia, and so resistance to evolutionary change, include "the complexity of social behaviour. The more numerous the components constituting the behaviour, and the more elaborate the physiological machinery required to produce each component, the greater the inertia"(10). This account, which was formulated as a general sociobiological one relating to societies of creatures of all kinds, can be applied directly to explain the phenomena of stability and gradual change in language as a whole and in individual languages.

As regards the impact of the new view of language on philosophy, this has already been discussed at some length in chapter VII, particularly in terms of the significance of language for philosophy, the problem of meaning and the relation of perception and knowledge. In relation to each of these major topics, a theory of language, as deriving its natural character from structural integration with the processes underlying perception and action, can make an important contribution towards extricating philosophers from some of the impasses in which they have long been imprisoned; it may not be too optimistic to suggest that this new approach could lead to actual progress in philosophy, something which otherwise has been rather infrequent, and may provide a basis for conciliation between those philosophers who take the view that all philosophy is a critique of language and those, like Popper, who consider that science matters and language does not (and that of Wittgenstein who, in describing other philosophers as flies buzzing in a bottle and unable to get out, was in his concern with language just as much himself the fly in a bottle). Though it is not possible to discuss the subject here because it would require too extensive a digression, there seems particular reason to think that the new view of language presented in this book ought to have a major impact on the foundations of logic; language, as has been said earlier, can only constitute a skeleton representation of the perception or action to which it relates, and logic (as historically and systematically heavily dependent on the syntactic structure of language) is no more than a skeleton of a skeleton. If language and syntax are structured by reality (as transmitted via perception and action), then logic, at one remove, also can only derive its structure and validity from perception and action, from what Royce describes as "the unavoidable structure of our experience"(13). The concepts of necessity and causation originate not in language, and not in logic, but in what Hegel describes as the 'logic of life', in the sequences of causes we perceive in our own action and, by transfer, in the action of others or of inanimate objects.

So far, this Conclusion has spoken about language as the subject-matter of linguistics, about language as correlated with vision and action in the brain, about language as an evolutionary process and language in philosophy and logic. But language in fact is multifarious. Besides the specialised languages and approaches to language which have been discussed, there is language as it is used in everyday life (the medium of social interaction), language as used in science (attempting to give a regular and permanent form to the unifying perceptions of scientists and within which there are many special sub-languages) and finally, and perhaps most important, there is language which transforms minds, changes consciousness - the language of poetry, of oratory and persuasion, of conversion. The extraordinary development of language, forming scientists of different nations into one global community, the almost miraculous power of language displayed in the ability to formulate and comprehend the most penetrating and intricate thought, reaches its culmination in the use of the total resources of language that poetry and oratory constitute. In these remarkable, special uses of language, there is a whole world for further exploration, for which the structural integration of language, sight and action, is of supreme importance. Two quotations, from Wittgenstein and from Saint-John Perse, particularly about the poetic use of language: "Worte eines Dichters können uns durch und durch gehen" (Wittgenstein Zettel (14)) and "Du savant comme du poéte, la pensée desintéressée. Car l'interrogation est la même qu'ils tiennent sur un même abîme et seuls leurs modes d'investigation diffèrent. Cette nuit originelle où tâtonnent deux aveugles-nés: le mystère est commun"(15).

To explain something - language, perception, thought - (or even to attempt to explain something) is not to explain it away. Each human function, language, perception, retains its immense potentialities. As language considers language and perception perceives perception, and the structure of what we come to know in finer and finer detail is expressed permanently in language, we are ourselves part of an unceasing development. The mind sees itself in all it sees, the world interprets itself through us and we realise that it is the nature of man to be a mirror of the world as well as a part of the world he mirrors. The individual has the privilege of seeing, from within the system, the development of the system of which he forms part - the society, the evolutionary process, the development of consciousness. He can see, and record, the ever-growing complexity of his own brain so that it can become an ever more accurate analogue of the structure of external things - and so that eventually there can develop, within his analogue of the world, an analogue of his own processes of language, perception and consciousness. The brain begins to understand its own nature, its own understanding.