I am not interested to know whether vivisection produces results that are profitable to the human race...The pain which it inflicts upon unconsenting animals is the basis of my enmity toward it, and it is to me sufficient justification without looking further.
—Mark Twain
apostrophe
Words that are spoken to a person who is absent or imaginary, or to an object or abstract idea. The poem God's World by Edna St. Vincent Millay begins with an apostrophe: "O World, I cannot hold thee close enough!/Thy winds, thy wide grey skies!/Thy mists that roll and rise!"