Dietrich of Freiberg (c.1250–after 1310)

In his work on the rainbow, De iride et radialibus impressionibus (On the Rainbow and Radial Impressions), Dietrich makes extensive use of experimental observation. He also wrote a number of other, more theoretical works including De esse et essentia (On Existence and Essence) and De intellectu et intelligibili (On Intellect and the Intelligible). In these works, Dietrich’s emphasis varies; his theological works tend to be heavily Neoplatonic, while his more secular philosophical works are more Aristotelian. Dietrich disagreed with Aquinas on certain metaphysical issues, and seems to have written in opposition to particular works by Aquinas.