As an undergraduate at Harvard, Oliver Wendell Holmes, Jr. wrote a fifteen-page critical essay on Plato -- which he passed on to Ralph Waldo Emerson for the poet's comments.

Emerson returned it with the following note: "When you shoot at a king, you must kill him."

["The safest general characterization of the European philosophical tradition," Alfred North Whitehead once famously remarked, "is that it consists of a series of footnotes to Plato." Holmes promptly destroyed the essay.]