Final answer:
The Greeks' greatest achievement was their contributions to medicine, astronomy, philosophy, and mathematics.
Step-by-step explanation:
The Greeks' greatest achievement was their contributions to various fields, including medicine, astronomy, philosophy, and mathematics. In medicine, Greek scholars like Hippocrates made pioneering discoveries that laid the foundation for modern medical practices. In astronomy, Greek scientists such as Aristarchus developed advanced understanding of celestial bodies and proposed a heliocentric model of the universe. In philosophy and mathematics, Greek philosophers like Aristotle and Pythagoras made significant contributions to logic, ethics, and geometry. These achievements showcase the Greeks' mastery of intellectual pursuits rather than ancient warfare techniques.