Whose name in Greek means 'the man from God who acted like a dog, was a follower of Socrates and free spirit who refused to conform to social conventions and has an antagonistic relationship with the authorities of his time?

Diogenes of Sinope

Explanation:

Diogenes of Sinope was a Greek philosopher and founder of the Cynic school who advocated self-control and the pursuit of virtue through simple living. He is said to have once wandered through the streets of Athens with a lantern in daylight, searching for an honest man. He had an antagonistic relationship with the authorities of his time.