Alexander of Hales, O.F.M., (ca.

1185 – 21 August 1245) (also Halensis, Alensis, Halesius, Alesius) also called Doctor Irrefragibilis (by Pope Alexander IV in the Bull De Fontibus Paradisi) and Theologorum Monarcha, is a theologian and philosopher important in the development of Scholasticism and of the Franciscan School.