ABSTRACT
Theophrastus of Eresus was born on the Greek island of Lesbos, about fifteen years after the foundation of Plato’s Academy. Theophrastus’ work was far from a simple continuation or imitation of Aristotle’s theories although he continued the enterprise initiated by Aristotle of collection and interpretation of information in every scientific field, and adopted some Aristotelian arguments. Theophrastus still held the idea of ensouled heavens and used the Aristotelian meaning of ‘pneuma’ (spirit or breath) to explain body processes but he denied the existence of ‘unmoved mover’. Theophrastus probably argues more against Plato’s theories than against Aristotle’s. It seems that Theophrastus was probably trying to develop a method of reasoning based on questioning, debating and opposition to existing theories, rather than forming a theory of his own. Theophrastus was the philosophical thinker who made scientific listing and classification indispensable and opened the way to real observation and research in natural sciences.
