  Heidegger takes off here from the second choral ode in Sophocles’ Antigone (which he discussed at length in 1935’s Introduction to Metaphysics). For Sophocles’ Theban elders, the one thing humanity cannot master is death. For Heidegger, thinking about death opens us up to the terrifyingly “awesome” insight that the known rests on the unknown, the mastered on the unmastered, like a small ship floating on a deep and stormy “sea” (IM 159, 164/GA40 159,  162).[44] We like to believe that humanity is well on its way to mastering the universe, but art teaches us that we are far from having exhausted the possibilities inherent in intelligibility.