Of Tranquillity. Ethical Commentaries: the work on Wellbeing is not to be found. So much for the ethical works. The physical works are these : III. The Great Diacosmos (which the school of Theophrastus attribute to Leucippus). The Lesser Diacosmos. Description of the World. On the Planets. IV. Of Nature, one book. Of the Nature of Man, or Of Flesh, a second book on Nature. Of Reason. Of the Senses (some editors combine these two under the title Of the Soul). V. Of Flavours. Of Colours. Of the Different Shapes (of Atoms). Of Changes of Shape. VI. Confirmations (summaries of the aforesaid works). On Images, or On Foreknowledge of the Future. On Logic, or Criterion of Thought, three books. Problems. So much for the physical works. The following fall under no head : Causes of Celestial Phenomena. Causes of Phenomena in the Air. Causes on the Earth's Surface. Causes concerned with Fire and Things in Fire.