A Protestant opponent of Aristotelean views, Nicolaus Taurellus wrote several times against Cesalpino. The "in re" structuralism ("in the thing") is the equivalent of Aristotelean realism. Such is the Aristotelean solution of the problem of universals. In Aristotelean syllogistic, they correspond respectively to the two argument forms, Barbara and Celarent. His moral philosophy was Aristotelean, arguing for conduct in the middle ground between extremes.