 Question one. Who said that meaning is just eight in the head? Wittgenstein. No, I'm sorry. It was Hilary Putnam. Question two. What philosopher wrote On Liberty? David Hume. Nope. John Stuart Mill. Question three. Which 17th century philosopher said, without God, nothing can be conceived? Barclay. It was Spinoza. Question four. Who said, life must be understood backward, but it must be lived forward?