Full Idea
Philolaus was the first person to affirm that the earth moves in a circle.
Gist of Idea
Philolaus was the first person to say the earth moves in a circle
Source
report of Philolaus (On the Cosmos (lost) [c.435 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 08.Ph.3
Book Reference
Diogenes Laertius: 'Diogenes Laertius', ed/tr. Yonge,C.D. [Henry G. Bohn 1853], p.372