The first medieval theologian to develop a systematic treatise on free will, the virtues, and the natural law. 586J   Guillermus Altissodorensis, or William of Auxerre, c.1150-1231 Summa aurea in quattuor libros sententiarum :  a subtilissimo doctore Magistro Guillermo altissiodore[n]si edita. quam nuper... Continue Reading →