The foundation of scientific biology can be seen as one of the greatest achievements of Aristotle and his colleague Theophrastus. Yet this universal interest in biology, as manifested in the Aristotelian corpus and the writings of Theophrastus, was not shared by their Peripatetic successors. Biological research in the Lyceum is rare and, a fact much more important, what gets lost is the insight into Aristotle’s scientific research program, which structured research into two parts: first a collection of facts, which then were interpreted primarily in regards to “form” and “function.” We have here a “Hellenistic mystery,” whose causes James Lennox tried to explore some years ago. 1