In striking contrast to the elucidation of the cause and progress of various diseases by modern methods of examination, the phenomena of epilepsy, although long and widely studied, remain, to a very large extent, obscure. In recent years, however, some definite although dissociated facts have become known, and abiding views formed, from therapeutic and pathological data, and, within the last few years, from the investigation of the heredity of those afflicted. Although these facts may be comparatively few in number, it is surprising that no attempt is made even in the most recent text-book, to correlate such facts as are known and accepted, and to formulate a comprehensive theory which could be tested by experiment and further and independent observation.