How did learning to read save Frederick Douglass?

According to Frederick Douglass, slaveowners denied their slaves the ability to read and write because they feared that literacy would provide slaves with knowledge and self-sufficiency that would threaten slaveowners' abilities to control their slaves. Additionally, keeping slaves illiterate ensured it would be nearly impossible for slaves to control the national perception of slavery because they would be unable to contribute their own narratives. Douglass believes his education was crucial to freeing himself for these reasons. Additionally, the texts he used to become literate provided him with intellectual defenses against slavery that he used throughout his career as an abolitionist. Specifically, Douglass references a speech about Catholic emancipation in The Columbian Orator that inspired much of his anti-slavery writing throughout his life.