* Democritus's Atomic Theory: Democritus, a Greek philosopher, proposed the idea of atoms around the 5th century BC. He believed that all matter was composed of indivisible particles called "atomos" (meaning "uncuttable" or "indivisible").

* The Core Idea: The key point of Democritus's theory was that atoms could not be divided further. They were the fundamental building blocks of everything.

So, the answer is no, Democritus did not think an atom could be divided.

However, it's important to note:

* His theory was based on philosophical reasoning, not scientific experimentation. He didn't have the tools or techniques to test his ideas.

* Later advancements in science: It wasn't until much later, in the 19th century, that scientists like John Dalton began to develop a more scientific atomic theory. Dalton's theory, based on experimental evidence, also initially assumed atoms were indivisible.

* The discovery of subatomic particles: In the 20th century, the discovery of protons, neutrons, and electrons proved that atoms were, in fact, divisible.

In summary: While Democritus's atomic theory was a remarkable idea for its time, it was eventually superseded by more advanced and accurate scientific models.