during May 15, 16, and 17, 1975. The Proceedings constitute this volume. At this Symposium we intended to realize sentiments which Sir John Eccles ex­ pressed as director of a Study Week of the Pontificia Academia Scientiarum, CiWl del Vaticano, in the fall of 1964: "Certainly when one comes to a [study] . . . devoted to brain and mind it is not possible to exclude relations with philosophy" ([5], p. viii). During that study week in 1964, a group of distinguished biomedical and behavioral scientists met under the director­ ship of Sir John C. Eccles to relate psychology to what Sir John called 'the Neurosciences. ' The purpose of that study week was to treat issues con­ cerning the functions of the brain and, in particular, to concentrate upon the relations between brain functions and consciousness.