Along with the opposable thumb, man's greatest evolutionary gift is his mind. A neurological masterpiece unsurpassed until the 22nd century, the human mind seeks to categorize and classify, to control the unknown. Science is an expression of this core evolutionary need. The earliest record of scientific endeavors date to the Mesopotamian cultures. There, wise men catalogued astronomical observations, mineral descriptions, and the symptoms of disease. By the time of the Greeks, Thales, Aristotle, and Plato had laid down the fundamentals of logic, which would later lift man into the Industrial Age and beyond.