Summary:William G. Lennox, author ofEpilepsy and Related Disorders, had a lasting effect on our understanding of this illness. He postulated that epilepsy was not a unitary condition and that neuronal chemistries differed from one form of the disease to another. A leader in the use of electroencephalography in epilepsy, he described the first nearly pathognomonic EEG pattern and demonstrated specific features for each of the three most common types of seizure. His pioneering investigations into the biochemical basis of epilepsy helped to identify pathological mechanisms in epileptic attacks. Lennox stood alone in his belief, now generally accepted, that the genetics of epilepsy could be understood only through a multifactorial mode of inheritance. The author presents an affectionate portrait of the physician, the teacher and the man, the founder of the Seizure Unit and the unifying force in the study of epilepsy by both professionals and lay persons.