One hundred and twenty years ago, J. Jackson summarized the results of his research in his seminal lecture, where he used epilepsy, as a model for the analysis of the structural-functional organization of the central nervous system. He revealed a mechanism of epileptic seizure and showed that any epilepsy, including the «genuine» one, had focal start. However, a dichotomic conception became firmly established later. In this article, basic stages of further development of the problem are discussed and contribution of the Russian-Soviet-Russian neurological school to the return on the modern level to Jackson’s unitary conception of epilepsy and a role of epileptic systems forming different courses of epileptic activity flow from epileptic focus to other cerebral structures are emphasized.