Best paraphrase of lines 3-5 of a lecture upon the shadow

Satire is a genre of literature in which the vices, shortcomings and excesses of a person, institution or society at large are held up to ridicule. Satire often has a social or political purpose, as the writing is often meant to shame these entities into improvement.

Satire most often uses humorous language, but this does not mean that it cannot deal with serious topics. In fact, satire is especially useful when we need to address a serious, difficult topic, and offer social criticism, in a nonthreatening way. This is the case with "Uncle John's Farm." Although the author talks about serious topics, such as slavery and racism, he does so in a way that proves to be more accessible and less threatening than it would be if these topics were discussed in a serious tone.