One of the bright representatives of E.-Syr. mysticism. Nothing is known of his life, except that he was a renowned physician at the time of Cath. Ḥenanishoʿ I (685/6–692/3); he was also known as Luqa, while in the ms. tradition he is referred to as ‘a disciple of Rabban Shabur’ (middle of the 7th cent.), which implies either that he was his direct disciple or that he resided in the monastery of Rabban Shabur (modern southwest Iran). ʿAbdishoʿ bar Brikha attributes to him three books: on the monastic life; on medicine; and on the interpretation of the mysteries of the cell. Whereas the first and the third title seem to correspond to the extant ‘Book of Grace’ (attributed in the W.-Syr. ms. tradition to Isḥaq of Nineveh; for the list of mss., see Vööbus) and the memrā ‘On the consecration of the cell’ (ms. olim Alqosh, Notre-Dame des Semences; Vosté 237 and its later copies), respectively, his medical work is known only from the quotations in the Lexicon of Bar Bahlul. ʿAbdishoʿ’s list is to be supplemented by a group of short fragments of unidentified provenance preserved in the aforementioned Alqosh ms. as well as by sentences of mystical content (ms. Sharfeh, Rahmani 80, and the lost ms. Siirt 109). Moreover, Ishoʿdnaḥ attributes to him a life of Mar Gani, which seems to be lost. His mystical works were used both by E.-Syr. (e.g., Yawsep Ḥazzaya) and W.-Syr. authors (e.g., Bar ʿEbroyo).

The probable explanation of the name of Shemʿon d-Ṭaybutheh (lit. ‘of his grace’) is that it derives from the title of his book, viz. the ‘Book of Grace’. The history of scholarship on this text and its authenticity proceeded from the acceptance of the authorship of Isḥaq based predominantly on the data provided by mss. (Vööbus, Bunge) to the critical investigation of a wider scope which resulted in the plausibility of the attribution to Shemʿon with acknowledgment of strong influence of Isḥaq’s writings upon Shemʿon (Miller, Bettiolo). The comparative study of the ‘Book of Grace’ in the context of the extant works of Isḥaq and Shemʿon as well as of the interrelationship of the ms. tradition of their works still remains a desideratum.

Although Shemʿon evidently draws on the authoritative writings of Evagrius of Pontus, Mark the Monk, Pseudo-Dionysius the Areopagite, Makarios, etc., it is not yet clear how he interpreted the tradition, while developing original doctrine with emphasis on the role of the divine grace in the life of the monk and special attention to the issue of interdependence between the body and the spiritual life.