Bardaisan (11 July 154 – 222 AD; Syriac: ܒܪ ܕܝܨܢ, Bar Dayṣān; also Bardaiṣan), known in Arabic as ibn Dayṣān (Arabic: ابن ديصان)[1] and in Latin as Bardesanes, was a Syriac-speaking Assyrian[2] Christian writer and teacher with a gnostic background,[3] and founder of the Bardaisanites.
A scientist, scholar, astrologer, philosopher, hymnwriter,[4] and poet, Bardaisan was also renowned for his knowledge of India, on which he wrote a book, now lost.[5] According to the early Christian historian Eusebius, Bardaisan was at one time a follower of the gnostic Valentinus, but later opposed Valentinian gnosticism and also wrote against Marcionism.[6]