What does Frederick Douglass mean when he says "Bread of Knowledge"?

Douglass' use of the word "bread" suggests that knowledge is as necessary to human life as is food.

Furthermore, Douglass is clearly playing upon his readers' knowledge of the Bible. (His memoir was intended as an argument against slavery.) In the Bible, references to bread in the New Testament are numerous, and Jesus' body itself is equated with bread, among other things.

The Lord's Prayer is Jesus' own words in which he asks for "our daily bread"--the stuff of life here are again directly equated to our spiritual well-being.

Therefore, bread, and by metaphor, knowledge, take on a sacramental, holy quality for Douglass, and, he hopes, in the minds of his readers.

Knowledge, for Douglass and his audience, is not merely a matter of literacy, it is also about becoming fully human, and fully capable of developing spiritually, morally and emotionally.