 Plutarch paid special attention to “physics,”, which in antiquity included metaphysics, natural philosophy, psychology and theology. His most important surviving works in metaphysics are those related to the interpretation of the Timaeus, namely On the Generation of Soul in the Timaeus (De animae procreatione in Timaeo), On Isis and Osiris (De Iside et Osiride); from lost works of Plutarch relevant are the following: Where are the Forms? (#67), How Matter Participates in the Forms: It Constitutes the Primary Bodies (#68), On the World's Having Come into Beginning According to Plato (#66), On Matter (#185), On the Fifth Substance (#44). Plutarch shows quite some interest in the explanation of natural phenomena in several surviving works, most importantly in: On the Face Which Appears in the Orb of the Moon (De facie quae in orbe lunae apparet), On the Principle of Cold (De primo frigido), On the Cleverness of Animals (De sollertia animalism). Plutarch's interest in this area is apparently motivated by the wish to develop Platonist natural philosophy and also oppose the Stoics, who were dominant in this field especially since Posidonius (1st c. BCE), and in Plutarch's age with his much older contemporary Seneca (ca. 1BCE–65CE), the author of Naturales Quaestiones. Given the importance of god in the world's coming into being according to Plutarch, he is seriously engaged with theology, especially with questions pertaining to the relation between god and man, such as the issue of divination, divine justice and divine punishment, and so on, in: On Oracles at Delphi (De Pythiae oraculis), On the Obsolescence of Oracles (De defectu oraculorum), On the E at Delphi (De E apud Delphos), On Delays in Divine Punishment (De sera numinis vindicta), and On the Daemon of Socrates (De genio Socratis Socratis). Plutarch's On the Generation of Soul in the Timaeus together with the ten Platonic Questions illustrate well his work as a Platonic exegete (see Hershbell 1987, Ferrari 2001). Like the former work, most of the Platonic Questions also deal with metaphysics and psychology (Questions I and III are concerned with epistemology, VII with physics, and X with language).