“TWO WRONGS DON’T MAKE A RIGHT”
First, Socrates discourages the bribing of the guards on the grounds that two wrongs don’t make a right. “[W]e ought not to retaliate or render evil for evil to anyone, whatever evil we may have suffered from him.” Yes, there are problems in that an innocent man is condemned to death, but what happens to the integrity of a man if when he disagrees with an evil that he responds with an evil? This principle is so absolute these very words appear almost verbatim nearly 500 years later in the writings of The Apostle Paul and Peter (Romans 12:17; 1 Thessalonians 5:15; 1 Peter 3:9*). Crito felt his reputation was at stake if he stood by and let Socrates be executed, but Socrates saw the bigger picture and by going ahead with his death, saved Crito from compromising his integrity by making the bribes.
Second, Socrates provides three reasons as to why he should remain in prison, the first being a metaphor of the State acting as his parent. His actual parents were legally wed by the laws of the State, he was born into the State and educated by the State. In effect, the State gives him identity, so if he were to escape, he would be disobeying his parent, the State. The second reason to stay in prison and go on to death is that the State has been generous, so what gratitude does he show by running away? The final reason is that by receiving the sentence of death, Socrates entered into an agreement with the State--and everyone should keep their agreements. Escape would be in violation to the agreement. Besides, what power remains in the State if he flees his prison?
* One wonders if this was a common teaching, of not repaying evil for evil, for it pre-dates King Solomon who lived roughly 500 years before Socrates. Solomon included this saying in his collection of Proverbs.