Hughlings Jackson's neurological ideas.

Hughlings Jackson's neurological ideas are scientifically valid and practically useful. He began by emphasizing the focal lesion as the key to analysing patients' symptoms. He proclaimed that 'Epilepsy is the name for occasional, sudden, excessive, rapid, and local discharge of grey matter.' He eliminated any need for a direct appeal to metaphysical agents by asserting that the nervous system is an exclusively sensorimotor machine constrained by the newly discovered conservation laws. In constructing his neurophysiology he accepted the phrenological assumption that the nervous system is composed of a number of physiologically discrete organs, each with a single function accessible to the diagnostician. By observing the march of epileptic seizures he developed the idea of somatotopic representation. He claimed that the nervous system is an evolutionary hierarchy of three levels connected by the process of weighted ordinal representation. His assertion of the Doctrine of Concomitance further separated the concerns, and the institutions, of the neurophysiologist from that of the psychiatrist. He came to reject the idea of the unconscious because he could not observe unequivocally unconscious behaviour at the bedside. Each of these ideas emerged from contemporaneous scientific streams, but Hughlings Jackson was the one to incorporate them into practical medicine. These neurological ideas gave physicians the methods, tools, principles and structures with which to establish a new science of clinical neurology.