5. Τοπικά: Topica: On dialectical syllogism (διαλεκτικὸς συλλογισμός), so called from consisting mainly of commonplaces (τόποι. loci), or general sources of argument.
6. Σοφιστικοὶ ἒλεγχοι: Sophistici Elenchi: On sophistic (σοφιστικὸς) or eristic syllogism (ἐριστικὸς συλλογισμός), so called from the fallacies used by sophists in refutation (ἒλεγχος) of their opponents.
[Numbers 1-6 were afterwards grouped together as the Organon.]
B. Physical
1. Φυσικὴ ἀκρόασις: Physica Auscultatio: On Nature as cause of change, and the general principles of natural science.
2. περὶ οὐρανοῦ: De coelo: On astronomy, &c.
3. περὶ γενέσεως καὶ φθορᾶς: De generatione et corruptione: On generation and destruction in general.
4. Μετεωρολογικά: Meteorologica: On sublunary changes.
5. † περὶ κόσμου: De mundo: On the universe. [Supposed by Zeller to belong to the latter half of the 1st century B.C.]
6. περὶ ψυχῆς: De anima: On soul, conjoined with organic body.