This density is what makes poetry a literature, which is to say it cannot exist without roots, without knowledge of earlier bodies of poetic expression. This is why when “Instapoetry” proudly declares itself a form of unknowing, it denies itself the power of the thing it claims to be. When the Instagram poet Charly Cox, for instance, writes of the history of poetry that “I didn’t know a thing,” but that it doesn’t matter because “I just knew how to feel,” the hollowness and, yes, the narcissism are distressingly naïve. Every poet from Sappho to Simone White has known that getting feeling into language isn’t the same thing as having feelings.