Plato's Apology has Socrates declare that the god attached him to the city as a gadfly to a large, well-bred but sluggish horse (Apology 30e), and the court convicted him on charges of impiety and corrupting the youth. Xenophon's Apology independently records the trial. His death by hemlock is narrated in the Phaedo.
The story told ever since: free speech's founding casualty, the man who died rather than stop talking. Every era recasts him in its own uniform: Enlightenment hero of reason, Romantic martyr, modern free-speech icon.
The structural reading: a stable society manufactures its own gadfly, an internal critic whose sting maintains the fiction of tolerance, and whose execution maintains the boundary. Athens needed Socrates exactly as much as it killed him. The gadfly is a civic organ with a death sentence built in.
If every age kills its gadfly and then builds statues to it, what is the statue actually for?