How Historical is the Flat Earth Theory?

Jessica Warren · September 29, 2026

We’ve all probably got into an argument with an internet stranger about whether our planet is round or flat. The phrase “flat earther” was originally used as a more tasteful way of calling someone an idiot, not that they actually believed that they could fall off the edge of the Earth.

However, for whatever reason, people with a vast library of knowledge have difficulty wrapping their minds around the idea that our planet is spherical. But how historical is this belief? Did people of ancient civilizations actually believe our planet was flat?

The “Flat Earth Theory”

First of all, let’s address the very theory these scientifically illiterate group of numbskulls are trying to push. From a historical standpoint, the “Flat Earth Theory” does not exist. However, different cultures from different times shared the notion that our planet was flat.

This view was held by the Ancient Greeks, as well as China and India, but their explanation of the Earth’s flatness differed. For instance, the Ancient Greeks thought that the planet was disk-like in shape but was surrounded by a spherical sky and heavens. Indians widely believed that the lands were divided into four continents and surrounded by unscalable mountains. The ancient people of modern-day Papua New Guinea envisioned a planet that was limited to what the eye could see—past the sea on the horizon, there was nothing else to explore.