Micromégas (1752)
The French philosopher Voltaire wrote this novel about the titular alien who hails from a planet that orbits the star Sirius. After a small bit of scientific heresy, Micromégas decides to spend his 800-year exile traveling around the galaxy with a bit of help from the forces of attraction and gravity. He eventually arrives on Saturn and befriends one of the minuscule scholars there. They decide to travel to Earth, which the two deem to be lifeless until one of them spots a tiny speck that turns out to be a boat. Did I mention the Saturnian was 1.2 miles tall and Micromégas is 24 miles tall? No? My bad. The two fashion a system of communicating with humans, who eventually start telling the aliens about different philosophies, which they find flawed at best and infuriating at worst.
