The external causes are: falling, percussion of the nerves, attrition, and cutting across of the nerves; also anger, fear and excess of cold that compresses, excess of heat that scatters; also taking hold of the fish called ‘tarcon’.577 And Avicenna, with profitable briefness, calls everything paralysis which binds and compresses the end and origin of the nerves, so that the spirit cannot pass through them. It comes oftenest from the following; phlegm, and less often from melancholy, still less often from sanguine humour, and least of all from choler, except it be mixed with another humour. Also it is caused by an imposthume, or by the crisis of the four sicknesses, namely, the falling sickness, colic, suffocatio matricis, and apoplexy.