What parallels, or similarities, so you see between the books douglass reads and his own life?

Frederick Douglass was a former slave who, after becoming a free man, was an abolitionist, a writer and an orator. He was only able to learn how to read at age 12 and he would read whatever he could find: poems, newspapers, books, political pamphlets... He also owned a private library at home. Douglass believed that what he could learn from books could never be taken away from him - it would make him more aware and knowledgeable and that meant freedom to him. That said, this is the main parallel between his old life (as a slave), his new life (as a free man) and the books he read (which would enable him to learn new things on a daily basis): all those situations mentioned above meant freedom to Douglass.  

an expression designed to call something to mind without mentioning it explicitly; an indirect or passing reference.