The time for such argument is past.
At a time like this, scorching irony, not convincing argument, is needed.

Oh! had I the ability, and could I reach the nation's ear, I would to-day pour out a fiery stream of biting ridicule, blasting reproach, withering sarcasm, and stern rebuke.

For it is not light that is needed, but fire; it is not the gentle shower, but thunder.

We need the storm, the whirlwind, and the earthquake.

The feeling of the nation must be quickened; the conscience of the nation must be roused; the propriety of the nation must be startled; the hypocrisy of the nation must be exposed; and its crimes against God and man must be proclaimed and denounced.
What to the American slave is your Fourth of July?
I answer, a day that reveals to him, more than all other days in the year, the gross injustice and cruelty to which he is the constant victim.