Over 200 neuroscientists met at the Max-Planck-Institut fur Biophysikalische Chemie in Gottingen between April 7th-9th 1983 in order to honour a foreign member of the Institute, namely Sir John Carew Eccles, who celebrated his 80th birthday on January 27th 1983. It was a lively scientific gathering of former students, colleagues and friends of Sir John and Lady Helena. We had all come together from different parts of the world to celebrate this occasion, which gave us the wonderful chance to meet the various members of a large family, united by respect and gratitude for Sir John. The lectures were based on the many themes which have been at the centre of John Eccles' scientific zeal throughout his life. Indeed the chapter headings of this book have been taken from the book titles of Sir John's own work. We would also have liked to publish the discussions which took place after every lecture and to each of which John Eccles contributed in his usual lively manner, but editing them would not have conveyed the stimulating atmosphere, which Sir John created.