William Lloyd Garrison was an American abolitionist who published a newspaper called The Liberator which was an abolitionist piece of literature and kept on publishing until the end of slavery. Reverend Lovejoy or Elijah Parish Lovejoy was a reverend who published anti-slavery articles in various newspapers. He also started an abolitionist paper called the Alton Observer.
Plato's teacher was Socrates so Socrates' direct methods were passed on down to Plato who reiterated them to his students.