Summary. This leading article is written bearing in mind the disparities between diferent texts and studies on epilepsy. Ihese concern the concet and the definition of epilepsy, although there is now little disparity in the classification of crises an syndromes. We also consider the increasing tendency to inchude other disorders with their own names and characteristics within the concept of epilepsy. Many of these disorders are also characterized by mental retardation, dementia and neurological deterioration. This contributes to maintain the sombre, ominous concept implicit in the word 'epilepsy' for centuries and is a major factor in the social discrimination of people with epilepsy. We suggest a concept and definition of the disorder diferen- tiating it from epileptic crises and other processes /REV NEUROL 1999· 28: 1159-611