This is part of a series on science discoveries which looks at the implications of the discoveries today. For the ancient Greeks science formed part of their study of philosophy, foremost amongst the philosophers of the time was Aristotle. The book describes the historical context in which he lived and explains how Plato encouraged him and other philosophers to let their mind and thoughts roam free in the pursuit of knowledge. On Plato's death Aristotle left to travel and it is explained how he carried out many observations on nature which was contrary to the methods of the time. In his search for an underlying order in nature he described embryology and animal development which was hardly improved upon until the 1600s. Later Aristotle tried to analyze the way language is used as a means or an instrument to express knowledge and developed his versions of dialectic. The book then describes the legacy of Aristotle and the ways in which his understanding, his skill at asking the right questions and his reliance on observation and first-hand evidence stimulated scientists such as Galileo Galilei, Isaac Newton and Charles Darwin.