Other related topics at: Literary Topics 210. Poetry (defining) Boswell: "Then, Sir, what is poetry?" Johnson: "Why, Sir, it is much easier to say what it is not. We all know what light is; but it is not easy to tell what it is." Boswell: Life Link 1,042. Poetry (Defining) "Poetry is the art of uniting pleasure with truth, by calling imagination to the help of reason." Johnson: Milton (Lives of the Poets) Link