Neme'sius（*Neme/sios). 1. The author of a Greek treatise, Περὶ Φύσεως Ἀνθρώπου, De Natura Hominis, of whose date and personal history little is known. He is called bishop of Emesa, in Syria, in the MSS. of his work, and also by Anastasius Nicenus (Quaest. in S. Script. ap. Biblioth. Patrum, vol. vi. p. 157, ed. Paris, 1575), and was evidently a Christian and a man of piety. The time in which he lived cannot be determined with much exactness, as the only ancient writers by whom he is quoted or mentioned are probably Anastasius and Moses Bar-Cepha (De Parad. 1.20, p. 55, ed. Antw. 1569), which latter author calls him " Nu-mysius Philosophus Christianus." He himself mentions Apollinaris (p. 77, ed. Oxon.) and Eunomius (p. 73), and therefore may be supposed to have lived at the end of the fourth or beginning of the fifth century after Christ. He has sometimes been confounded with other persons of the same name; but, as these erroneous conjectures have already been corrected by other writers, they need not be noticed here particularly.
Περι Κατασκυῆς Ἀνθρώπου, De Hominis Opificio, written by St. Gregory to complete the Henaemeron of his brother St. Basil. The treatise by Nemesius is an interesting philosophical little work, which has generally been highly praised by all who have mentioned it. The author has indeed been accused of holding some of Origen's erroneous opinions, but has been defended by his editor, bishop Fell, who, however, confesses that, with respect to the pre-existence of souls, Nemesius differed from the commonly received opinion of the Church. (Annot. p. 20.) Probably the principal source of the celebrity obtained by Nemesius is his having been brought forward as a person who was aware of the functions of the bile, and also of the circulation of the blood; and the passages which have been supposed to contain these doctrines are certainly sufficiently striking to deserve to be given here at full length. The former is as follows (100.24, p. 242, ed. Matth.):--" The motion of the pulse (called also the vital power) takes its rise from the heart, and chiefly from the left ventricle ........ The artery is, with great vehemence, dilated and contracted, by a sort of constant harmony and order, the motion commencing at the heart. While it is dilated, it draws with force the thinner part of the blood from the neighbouring veins, the exhalation or vapour of which blood becomes the aliment for the vital spirit. But while it is contracted, it exhales whatever fumes it has through the whole body and by secret passages, as the heart throws out whatever is fuliginous through the mouth and nose by expiration." The other passage is almost equally curious (100.28. p. 260):--"The yellow bile," he says, "is constituted both for itself and also for other purposes; for it contributes to digestion and promotes the expulsion of the excrements; and therefore it is in a manner one of the nutritive organs, besides imparting a sort of heat to the body, like the vital power. For these reasons, therefore, it seems to be made for itself; but, inasmuch as it purges the blood, it seems to be made in a manner for this also." It is hardly necessary to say, that these passages are far enough from proving that Nemesius had anticipated the discoveries of Harvey and Sylvius; but at the same time they show that the ancients had advanced much farther in the path of science than is commonly supposed.