"What did Socrates die for?"
The Death of Socrates, by Jacques-Louis David
Public DomainThe Death of Socrates, by Jacques-Louis David

Socrates (469-399 BCE), one of the greatest Classical philosophers, was sentenced to death by the city-state of Athens after being found guilty on a charge of corrupting the youth of the city.  He was called a "gadfly" of the state because of his outspoken opposition to the social and political status quo and it is probably this commitment to speaking truth to power to which Grogan refers.