The relation between body and mind is one of the oldest riddles that has puzzled mankind. That material and mental events may interact is accepted even by the law: our mental capacity to concentrate on the task can be seriously reduced by drugs. Physical and chemical processes may act upon the mind; and when we are writing a difficult letter, our mind acts upon our body and, through a chain of physical events, upon the mind of the recipient of the letter. This is what the authors of this book call the 'interaction of mental and physical events'. We know very little about this interaction; and according to recent philosophical fashions this is explained by the alleged fact that we have brains but no thoughts. The authors of this book stress that they cannot solve the body mind problem; but they hope that they have been able to shed new light on it. Eccles especially with his theory that the brain is a detector and amplifier; a theory that has given rise to important new developments, including new and exciting experiments; and Popper with his highly controversial theory of 'World 3'. They show that certain fashionable solutions which have been offered fail to understand the seriousness of the problems of the emergence of life, or consciousness and of the creativity of our minds. In Part I, Popper discusses the philosophical issue between dualist or even pluralist interaction on the one side, and materialism and parallelism on the other. There is also a historical review of these issues. In Part II, Eccles examines the mind from the neurological standpoint: the structure of the brain and its functional performance under normal as well as abnormal circumstances. The result is a radical and intriguing hypothesis on the interaction between mental events and detailed neurological occurrences in the cerebral cortex. Part III, based on twelve recorded conversations, reflects the exciting exchange between the authors as they attempt to come to terms with their opinions.

Sir John Eccles, a distinguished scientist and Nobel Prize winner who has devoted his scientific life to the study of the mammalian brain, tells the story of how we came to be, not only as animals at the end of the hominid evolutionary line, but also as human persons possessed of reflective consciousness.

Sir Arthur Stanley Eddington (1882-1944) was a key figure in the development of modern astrophysics, who also made important contributions to the philosophy of science and popular science writing. The Arthur Eddington Memorial Trust was set up after his death in order to hold annual lectures on the relationship between scientific thought and aspects of philosophy, religion or ethics. This 2012 collection gathers together six of these lectures, including contributions by Sir Edmund Whittaker, Herbert Dingle, Richard B. Braithwaite, John C. Eccles, Dame Kathleen Lonsdale, and Baroness Mary Warnock, together with Eddington's 1929 Swarthmore Lecture on Science and the Unseen World. A preface written by the Astronomer Royal, Baron Rees of Ludlow, is also included. This is a fascinating book that will be of value to anyone with an interest in the philosophy of science and Eddington's legacy.

The relation between body and mind is one of the oldest riddles that has puzzled mankind. That material and mental events may interact is accepted even by the law: our mental capacity to concentrate on the task can be seriously reduced by drugs. Physical and chemical processes may act upon the mind; and when we are writing a difficult letter, our mind acts upon our body and, through a chain of physical events, upon the mind of the recipient of the letter. This is what the authors of this book call the 'interaction of mental and physical events'. We know very little about this interaction; and according to recent philosophical fashions this is explained by the alleged fact that we have brains but no thoughts. The authors of this book stress that they cannot solve the body mind problem; but they hope that they have been able to shed new light on it. Eccles especially with his theory that the brain is a detector and amplifier; a theory that has given rise to important new developments, including new and exciting experiments; and Popper with his highly controversial theory of 'World 3'. They show that certain fashionable solutions which have been offered fail to understand the seriousness of the problems of the emergence of life, or consciousness and of the creativity of our minds.
In Part I, Popper discusses the philosophical issue between dualist or even pluralist interaction on the one side, and materialism and parallelism on the other. There is also a historical review of these issues.
In Part II, Eccles examines the mind from the neurological standpoint: the structure of the brain and its functional performance under normal as well as abnormal circumstances. The result is a radical and intriguing hypothesis on the interaction between mental events and detailed neurological occurrences in the cerebral cortex.
Part III, based on twelve recorded conversations, reflects the exciting exchange between the authors as they attempt to come to terms with their opinions.

The problem of the relation between our bodies and our minds, and espe cially of the link between brain structures and processes on the one hand and mental dispositions and events on the other is an exceedingly difficult one. Without pretending to be able to foresee future developments, both authors of this book think it improbable that the problem will ever be solved, in the sense that we shall really understand this relation. We think that no more can be expected than to make a little progress here or there. We have written this book in the hope that we have been able to do so. We are conscious of the fact that what we have done is very conjectur al and very modest. We are aware of our fallibility; yet we believe in the intrinsic value of every human effort to deepen our understanding of our selves and of the world we live in. We believe in humanism: in human rationality, in human science, and in other human achievements, however fallible they are. We are unimpressed by the recurrent intellectual fashions that belittle science and the other great human achievements. An additional motive for writing this book is that we both feel that the debunking of man has gone far enough - even too far. It is said that we had to learn from Copernicus and Darwin that man's place in the universe is not so exalted or so exclusive as man once thought. That may well be."

This book has had a three-fold origin, corresponding to the discoveries made by the three authors and their collaborators during the last few years - mostly since 1962. A most fruitful symposium on the cerebellum was held in Tokyo at the time of the International Physiological Congress in September 1965, and there was then formulated the project of writing this book so as to organize all this new knowledge and make it readily available, and to give opportunity for the con ceptual developments that may be seen in Chapters XI, XII and XV in particular. The present account of the physiological properties of the cerebellar cortex is based to a large extent on systematic investigations that were concerned with discovering the mode of operation of the constituent neuronal elements of the cerebellar cortex. This work was carried out in the Physiology Department of the Australian National University from 1963 to 1966 in collaboration with several visiting scientists - initially Drs. ANDERSEN, OscARssaN and VooRHOEVE and later Drs. LuNAs, SAsAKI and STRATA - to all of whom grateful thanks are extended for a great many of the figures, and even more significantly for the original and critical contributions that they made to so many aspects of this exploration into the mode of operation of the neural machinery of the cerebellar cortex.

The planning of this Study Week at the Pontifical Academy of Science from September 28 to October 4, 1964, began just two years before when the President, Professor Lemaitre, asked me if 1 would be responsible for a Study Week relating Psychology to what we may call the Neurosciences. 1 accepted this responsibility on the understanding that 1 could have as sistance from two colleagues in the Academy, Professors Heymans and Chagas. Besides participating in the Study Week they gave me much needed assistance and advice in the arduous and, at times, perplexing task that 1 had undertaken, and 1 gratefully acknowledge my indebtedness to them. Though there have been in recent years many symposia concerned with the so-called higher functions of the brain, for example with percep tion, learning and conditioning, and with the processing of information in the brain, there has to my knowledge been no symposium specifically with brain functions and consciousness since the memorable treating Laurentian Conference of 1953, which was later published in 1954 as the book, "Brain Mechanisms and Consciousness."

In this book the author has collected a number of his important works and added an extensive commentary relating his ideas to those of other prominentnames in the consciousness debate. The view presented here is that of a convinced dualist who challenges in a lively and humorous way the prevailing materialist "doctrines" of many recent works. Also included is a new attempt to explain mind-brain interaction via a quantum process affecting the release of neurotransmitters. John Eccles received a knighthood in 1958 and was awarded the Nobel Prize for Medicine/Physiology in 1963. He has numerous other awards honouring his major contributions to neurophysiology.

'An extraordinary achievement, and an excellent book.' - Sir Karl Popper

'A valuable contribution to a debate of considerable significance.' - Dr John Polkinghorne, Queen's College, Cambridge

'Epoch-making book ... a monumental achievement of synthesis and analysis, a fitting culmination to a lifetime devoted to understanding the human brain and the nature of the self.' - The Scientific and Medical Network

The human brain is the inner universe through which all external events are perceived. That fact alone should ensure that neuroscience will eventually receive top priority in the list of human endeavors. The brain represents the pinnacle of sophistication in the realm of living systems. Yet it is an imperfect organ, whose failures in disease processes lead to the occupation of more than half of all hospital beds and whose variable performance in the healthy state contributes in undetermined degree to the world's social problems. Every significant advance in or understanding of the brain has yielded enormous practical dividends. There is every reason to believe the future holds even greater promise. In the preface to our first edition, we drew attention to the establishment of graduate programs in dozens of universities around the world and the emergence of numerous international journals devoted to interdisciplinary work on the brain. The discoveries that have flowed from this activity have required extensive updating of the details of this book, which is a testimony to the fruitfulness of neuroscience research. Yet the basics remain the same. It is more important than ever that the neuroscientist be presented with the fundamental subdisciplines that together make up the total of brain research in an integrated manner.

I must thank my friend, Professor HANS WEBER, for being, as it were, the prime mover in causing this book to be written. He persuaded me in 1960 to contribute a review to the Ergebnisse der Physiologie. As originally planned, it was to be relatively short. However, the interest and scope of the whole subject of synapses stimulated me to write a much more comprehensive and extensive account. I was not even then satisfied, particularly as so many new and attractive investigations and ideas were being evolved during and after the writing of this review; and during the writing of this book most interesting developments are occurring in so many centres of research. Through the kind cooperation of my friends I have been given the opportunity to quote and even to illustrate from these new and fascinating developments before their final publication. There would be some justification if the author were to make the claim that this book is the fruit of a life-time of enquiry into the physiology of synapses. In 1927 the subject of Excitatory and Inhibitory Synapses was chosen for investigation in the course leading to the Oxford D. Phil. But there have been such remarkable developments during the last 12 years that in this book very little reference will be made to work earlier than 1951 except in the historical introductions.

In the brain information is coded into sequences of impulses which are unit responses travelling from neurones or nerve cells along nerve fibres. The neural code is equivalent to a Morse code of dots only in a great variety of temporal patterns and with thousands of connections in parallel. Fig. lA is a diagram of Figure 1: Drawing of Four Neurones of the Cerebral Cortex. This shows the excitatory synaptic connections set up by an input fibre from the thalamus labelled (spec. aff. ), which is an enormous nucleus in the brain that provides the principal inputs to the cerebral cortex. This spec. aff. fibre branches profusely to make excitatory synapses on the spiny stellate cell (Sst) and on one pyramidal cell (Pyr). All three pyramidal cells receive on their spines excitatory synapses from Sst, and there is a special excitatory structure, called by Szentagothai a cartridge, formed by the synaptic endings on the apical dendrites of two pyramidal cells. All three pyramidal cells but not the Sst, send their axons out of the cerebral cortex as shown by the lower projecting arrows. The upper inset shows an enlargement of a spine synapse with synaptic vesicles in the presynaptic ending and the spine arising from a dendrite. The lower two insets show diagrammatically normal and hypertrophied spine synapses. (SZENTAGOTHAI, 1978).

Sir Arthur Stanley Eddington (1882 1944) was a key figure in the development of modern astrophysics, who also made important contributions to the philosophy of science and popular science writing. The Arthur Eddington Memorial Trust was set up after his death in order to hold annual lectures on the relationship between scientific thought and aspects of philosophy, religion or ethics. This 2012 collection gathers together six of these lectures, including contributions by Sir Edmund Whittaker, Herbert Dingle, Richard B. Braithwaite, John C. Eccles, Dame Kathleen Lonsdale, and Baroness Mary Warnock, together with Eddington's 1929 Swarthmore Lecture on Science and the Unseen World. A preface written by the Astronomer Royal, Baron Rees of Ludlow, is also included. This is a fascinating book that will be of value to anyone with an interest in the philosophy of science and Eddington's legacy.