1270

- December - Crucial aspects of the philosophy of Averroism (itself based on Aristotle's works) are banned by the Catholic church in a condemnation enacted by papal authority at the University of Paris.

- The Summa Theologiae, a work by Thomas Aquinas that is considered within the Roman Catholic Church to be the paramount expression of its theology, is completed (year uncertain).

- Witelo translates Alhazen's 200-year-old treatise on optics, Kitab al-Manazir, from Arabic into Latin, bringing the work to European academic circles for the first time.

- The Sanskrit fables known as the Panchatantra, dating from as early as 200 BCE, are translated into Latin from a Hebrew version by John of Capua.

- Construction of the Old New Synagogue in Prague is completed.

- The cathedral on the Rock of Cashel in Ireland is completed.