Aristotle

Aristotle was an ancient Greek philosopher and scientist, and one of the greatest intellectual figures in history. No other philosopher had such a deep and long-standing impact on
Western science. As a philosopher and the earliest practitioner of the scientific method, his influence on western and islamic world is unmatched by anything else in history. In the fourth century BC he developed a fully comprehensive worldview that would stand for almost 2,000 years. Aristotle’s notions about science were questioned only by the rise of modern science in Europe in the 16th and 17th centuries. Aristotle’s intellectual range was vast, covering most of the sciences and many of the arts. Physics in the Aristotelian sense was a fundamental understanding of matter, change, causality, time, and space, all of which had to be consistent with logic and experience. From this he derived a cosmology that allowed him to explain all phenomena from everyday life to astronomy. Aristotle divided the theoretical sciences into three groups: physics, mathematics, and theology. Physics as he understood it was equivalent to what would now be called “natural philosophy,” or the study of nature; in this sense it encompasses not only the modern field of physics but also biology, chemistry, geology, psychology, and even meteorology. Aristotle adopted the view that the universe is ultimately composed of different combinations of the four fundamental elements of earth, water, air, and fire. Each element has a natural place in an ordered cosmos, and each has an innate tendency to move toward its natural place. Thus, earthy solids naturally fall, while fire, unless prevented, rises ever higher. According to Aristotle, the Earth is at the centre of the Universe, and around it the Moon, the Sun, and the other planets revolve in a succession of concentric crystalline spheres. The heavenly bodies are not compounds of the four terrestrial elements but are made up of a superior fifth element, or “quintessence.”