The most important aspect of this interpretation of Plato's metaphysics is the continuity between his teaching and the Neoplatonic interpretation of Plotinus or Ficino which has been considered erroneous by many but may in fact have been directly influenced by oral transmission of Plato's doctrine. A modern scholar who recognized the importance of the unwritten doctrine of Plato was Heinrich Gomperz who described it in his speech during the 7th International Congress of Philosophy in 1930. All the sources related to the have been collected by Konrad Gaiser and published as "Testimonia Platonica". These sources have subsequently been interpreted by scholars from the German "Tübingen School of interpretation" such as Hans Joachim Krämer or Thomas A. Szlezák.