The idea that Christians chose to celebrate the birth of Jesus on 25 December because this was the date of an already existing festival of the Sol Invictus was expressed in an annotation to a manuscript of a work by 12th-century Syrian bishop Jacob Bar-Salibi. The scribe who added it wrote: "It was a custom of the Pagans to celebrate on the same 25 December the birthday of the Sun, at which they kindled lights in token of festivity. In these solemnities and revelries the Christians also took part. Accordingly when the doctors of the Church perceived that the Christians had a leaning to this festival, they took counsel and resolved that the true Nativity should be solemnised on that day."