Our critical judgment in the case of expository books concerns their truth, whereas in criticizing belles-lettres, as the word itself suggests, we consider chiefly their beauty.

我们对说明书籍断关注是它们真实，而在评纯文学时，正如这词本身所暗示那样，我们主要考虑它们美感。

Do Main Street and The Grapes of Wrath belong in the category of belles-lettres or are both of them sociological studies, the one concentrating on urban experiences, the other on agrarian life?

《大街》和《葡萄》到底属于纯文学范畴，还是都属于社会学研究，一关注城市经验，一关注农村生活？