[62] There is a discussion of the relation of the Asclepiadae to temple practice in an article by E. T. Withington, 'The Asclepiadae and the Priest of Asclepius,' in _Studies in the History and Method of Science_, edited by Charles Singer, vol. ii, Oxford, 1921. During the development of the Coan medical school along these lines in the sixth and fifth centuries, there was going on a most remarkable movement at the very other extreme of the Greek world. Into the course and general importance of Sicilian philosophy it is not our place to enter, but that extraordinary movement was not without its repercussion on medical theory and practice. Very important in this direction was Empedocles of Agrigentum (_c._ 500-_c._ 430 B. C.). His view that the blood is the seat of the 'innate heat', εμφυτον θερμον {emphyton thermon}, he took from folk belief--'the blood is the life'--and this innate heat he closely identified with soul. More profitable was his doctrine that breathing takes place not only through what are now known as the respiratory passages but also through the pores of the skin. His teaching led to a belief in the heart as the centre of the vascular system and the chief organ of the 'pneuma' which was distributed by the blood vessels. This pneuma was equivalent to both soul and life, but it was something more. It was identified with air and breath, and the pneuma could be seen to rise as shimmering steam from the shed blood of the sacrificial victim--for was not the blood its natural home? There was a pneuma, too, that interpenetrated the universe around us and gave it those qualities of life that it was felt to possess. Anaximenes (_c._ 610-_c._ 545 B. C.), an Ionian predecessor of Empedocles, may be said to have defined for us these functions of the pneuma; ὁιον ἡ ψυχη ἡ ἡμετερα αηρ ουσα συγκρατει ἡμας, ὁλον τον κοσμον πνευμα και αηρ περιεχει {hoion hê psychê hê hêmetera aêr ousa synkratei hêmas, holon ton kosmon pneuma kai aêr periechei}, 'As our soul, being air, sustains us, so pneuma and air pervade the whole universe';[63] but it is the speculation of Empedocles himself that came to be regarded as the basis of the Pneumatic School in Medicine which had later very important developments. [63] The works of Anaximenes are lost. This phrase of his, however, is preserved by the later writer Aetios.