Why rizal challenge retana to duel?

José Rizal challenged Mariano P. de los Reyes Retana to a duel primarily due to Retana's critical portrayal of him in his writings, which Rizal considered defamatory. Retana had published a book that misrepresented Rizal's views and character, leading to a clash of honor. Rizal, valuing his reputation and integrity, sought to defend himself through the traditional means of a duel, a common practice for settling disputes of honor during that era. Ultimately, the duel did not take place, as it was a matter of principle rather than a genuine desire for violence.