This study offers a new and stimulating interpretation of Theophrastus' "De sensibus," a treatise unique in content and method, as it reports and criticizes the theories of sense perception of the Presocratics and Plato. Most of the material on the Presocratics is found nowhere else, which explains why many passages can be found scattered over the "Fragmente der Vorsokratiker," As an antidote to this fragmented approach the Presocratics are here studied in context, a text informed by a distinctly Peripatetic perspective. The analysis of the reports and (long neglected) criticisms of Plato (ch.4) and the Presocratics (ch.5) offers new insights into Theophrastus' exegetical procedure by succesfully using Peripatetic dialectic as a heuristic tool. The Epilogue outlines some implications for the role of the treatise in the doxographical tradition.