For many centuries, Christian writers accepted that Christmas was the actual date on which jesus was born. However, in the early eighteenth century, scholars began proposing alternative explanations. Isaac Newton argued that the date of Christmas was marked on December 25. In 1743, German Protestant Paul Ernst Jablonski argued Christmas was placed on December 25 to correspond with the Roman solar holiday Dies Natalis Solis Invicti and was therefore a "paganization" that debased the true church. In 1889, Louis Duchesne suggested that the date of Chrustmaa was calculated as nine months after the Annunciation (March 25), the traditional date of the Incarnation.