Theodorus of Cyrene

Theodorus (c. 340 – c. 250 BCE), also known as 'the Atheist', was an ancient Greek philosopher of the Cyrenaic school, originating from Cyrene. He taught that the ultimate aim of human life is to achieve joy and evade sorrow, with knowledge being the path to joy and ignorance leading to sorrow. He defined good as prudence and justice, and their opposites as bad, while considering pleasure and pain as indifferent. Theodorus held unconventional views on societal norms, asserting that actions like theft, adultery, and sacrilege were not inherently disgraceful if public opinion, formed by 'fools,' was disregarded. His principal claim to fame was his alleged atheism, earning him the epithet 'ho atheos' ('the atheist') from ancient writers. While some sources suggest he outright rejected the existence of gods, others propose he merely dismissed the popular deities. He was a disciple of Aristippus the Younger and studied under other philosophers. Banished from Cyrene, he later resided in Athens, where he faced accusations of impiety but was protected by Demetrius Phalereus. He also served Ptolemy I Soter and engaged in diplomatic missions, notably with Lysimachus, whom he famously defied with a witty remark about crucifixion. Theodorus's works, including a treatise 'On the Gods,' are lost, but his philosophical ideas influenced later thinkers like Epicurus.