 The first and main subject, occupying more than half of Theophrastus’ Metaphysics, is the nature and properties of first principles. More specifically, this treatise begins by demarcating the study of first principles as distinct from the objects of nature to which they are to be related. Next, it discusses the nature, number, identity and causality of first principles; the motion of celestial spheres, and how these connect to the sublunar world; the properties of first principles, i.e., whether they are indeterminate, determinate, or both, and how to understand their property of being at rest. The first part is followed by two extensive appendices, investigating problems relating to the main subject: (i) on epistemology, i.e., on determining the methods of knowing everything from first principles down to inanimate beings, and hence the nature of the connection between intelligibles and sensibles; and (ii) on teleology, i.e., on testing the alternative views of the application to the universe of a certain first principle, namely the principle that everything has a final cause and that nature does nothing in vain. It is particularly noteworthy that, in his Metaphysics, Theophrastus seems not to have been interested to explore some of the central themes of Aristotle’s thought, namely those concerned with the being qua being, the relation between form and matter and the problem of universals (see Sharples 2015).