This book is based on the papers delivered at an International Workshop on Multiple Sclerosis held in Erice, Italy from 29th August to 1st September 1983. The Meeting was organized with great efficiency in the delightful setting of the Centro di Cultura Scientifica Ettore Mahorana, by its Director, Antonino Zichichi, and was directed by the Editors of the Proceedings and by Professor C. Alvisi of the University of Bologna. The emphasis was deliberately on the contributions of laboratory science to the understanding of mUltiple sclerosis, its etiology, pathogenesis, diagnosis and treatment. Where so much is unknown, disagreement was expected and indeed welcome, and it is regrettable that it was not possible to publish verbatim the often animated and always interesting discussion. Differing views on the relevance of experimental allergic encephalomyelitis to multiple sclerosis were expressed by Dr. Wisniewski, Professor Seitelberger and Professor Alvord, who graphi- cally illustrated his changing beliefs over the years. Professor Seitelberger laid much greater emphasis on remyelination in remission in mUltiple sclerosis than had previously been the accepted view. The disorder of both humoral and cellular immunity in multiple scler- osis was discussed by Dr. Roos and Professor Link. Dr. Gilden described how recombinative techniques might be applied to the detec- tion of a virus in multiple sclerosis. The continued inability to detect any antigen to match the oligoclonal IgG bands in the CSF in multiple sclerosis patients was disappointing and there was an increasing tendency to regard the bands as "nonsense" antibodies.