The "Aphorismen über die Naturphilosophie" ("Aphorisms on Nature Philosophy"), published in the "Jahrbücher der Medicin als Wissenschaft" (1805–1808), are for the most part extracts from the Würzburg lectures, and the "Denkmal der Schrift von den göttlichen Dingen des Herrn Jacobi" ("Monument to the Scripture of the Divine Things of Mr. Jacobi") was a response to an attack by Jacobi (the two accused each other of atheism). A work of significance is the 1809 "Philosophische Untersuchungen über das Wesen der menschlichen Freiheit und die damit zusammenhängenden Gegenstände" ("Philosophical Inquiries into the Essence of Human Freedom"), which elaborates, with increasing mysticism, on ideas in the 1804 work "Philosophie und Religion" ("Philosophy and Religion"). However, in a change from the Jena period, evil is not an appearance coming from quantitative differences between the real and the ideal, but is something substantial. This work clearly paraphrased Kant's distinction between intelligible and empirical character. Schelling himself called freedom "a capacity for good and evil".