Gaius was the first Roman jurist to classify legal things into corporeal and incorporeal. His influential classification did not expressly mention the right of ownership. The German Pandectists justified this absence arguing that the list of tangibles referred to the objects of ownership. Following Pandectism, many modern legal systems acknowledge ownership only with regard to corporeal things. This paper departs from the Pandectists' conclusions. The categorization at issue should be read as part of Gaius's effort to educate his students for the legal profession. Gaius proposed a coherent classification embedded into a clear didactic project. The jurist was not seeking to advance a theory of ownership, but to link the legal actions to their objects.