The Aristotelian Propositional Inferential Way of Thinking

The heavens don't behave in this nice orderly fashion the way Aristotle and Ptolemy said they do. For example, if you look at Mars in the heavens, right, Mars will do this over time. People start to discover how chaotic the heavens actually are. If that's an illusion, what else isn't an illusion? How do you know any of this is real? Because all you have, be honest.