How did Theophrastus continue Aristotle’s work at the Lyceum?

As the successor to Aristotle at the Lyceum, Theophrastus maintained the school as a center for critical research rather than dogmatic adherence to a closed system. He embraced Aristotle’s philosophy across all fields, including metaphysics, psychology, and ethics, while working to strengthen the systematic unity of these subjects and reduce transcendental or Platonic elements.12

His contributions significantly expanded Aristotelian thought:

• Natural Science: He advanced the study of nature, particularly in botany and [mineralogy].1
• Logic: He was the first to seriously examine the logic of propositions. He developed theories of hypothetical syllogisms and "prosleptic" syllogisms, and he simplified modal syllogistic by redefining the nature of the "possible".31
• Ethics: He expanded upon Aristotle’s ethical work, notably through his Charaktēres, which provided detailed sketches of moral types.2

Under his leadership, the Lyceum reached its highest enrollment, solidifying its role as a primary institution for philosophical inquiry.2