Anaximander (610–546 BC), also from Miletus, was 25 years younger than Thales. He was a member of the elite of Miletus, wealthy and a statesman. He showed interest in many fields, including mathematics and geography. He drew the first map of the world, was the first to conclude that the earth is spherical, and made instruments to mark time, something like a clock. In response to Thales, he postulated as the first principle an undefined, unlimited substance without qualities (apeiron), out of which the primary opposites, hot and cold, moist and dry, became differentiated. His answer was an attempt to explain observable changes by attributing them to a single source that transforms to various elements. Like Thales, he provided a naturalistic explanation for phenomena previously given supernatural explanations. He is also known for speculating on the origin of mankind. He proclaimed that the earth is not situated in another structure but lies unsupported in the middle of the universe. Further, he developed a rudimentary evolutionary explanation for biodiversity in which constant universal powers affected the lives of animals. According to Giorgio de Santillana, a philosophy professor at the Massachusetts Institute of Technology, Anaximander's conception of a universe governed by laws shaped the philosophical thinking of centuries to come and was as important as the discovery of fire or Einstein's breakthroughs in science.
Anaximander (610–546 BC), also from Miletus, was 25 years younger than Thales. He was a member of the elite of Miletus, wealthy and a statesman. He showed interest in many fields, including mathematics and geography. He drew the first map of the world, was the first to conclude that the earth is spherical, and made instruments to mark time, something like a clock. In response to Thales, he postulated as the first principle an undefined, unlimited substance without qualities (apeiron), out of which the primary opposites, hot and cold moist and dry, became differentiated. His answer was an attempt to explain observable changes by attributing them to a single source that transforms to various elements. Like Thales, he provided a naturalistic explanation for phenomena previously given supernatural explanations. He is also known for speculating on the origin of mankind. He proclaimed that the earth is not situated in another structure but lies unsupported in the middle of the universe. Further, he developed a rudimentary evolutionary explanation for biodiversity in which constant universal powers affected the lives of animals According to Giorgio de Santillana, a philosophy professor at the Massachusetts Institute of Technology, Anaximander's conception of a universe governed by laws shaped the philosophical thinking of centuries to come and was as important as the discovery of fire or Einstein's breakthroughs in science.