Pseudo-Science 

Much of the knowledge about the natural world during the middle ages dates back to the teachings of the Greeks and Romans. Many did not question these ideas, despite the many flaws.

• Aristotle taught everything beneath the moon was comprised of four elements: earth, air, water, and fire.
• Greek astronomer Claudius Ptolemy thought that heavenly bodies such as the sun, moon, planets and various stars all revolved around the earth in perfect circles.
• The ancient Greeks and Romans held to the idea that illnesses were the result of an imbalance of four basic substances and was related to the theory of the four elements.