Aristotle is best known for his work about logic, reason, rhetoric, and politics, but he was also an avid scientist at a time when science was not much of a subject matter. It would be another 2,000 years before natural science would become a common profession, but Aristotle wrote Meteorology in the 4th century B.C., an ancient treatise that included his theories about the planet's phenomena. Aristotle's work described what to him was not readily explainable, including the evaporation of water and earthquakes.