The Sea-Wolf

Nietzsche's will to power:
What I am striving to express is this strength itself, more as a thing apart from his physical semblance.  It was a strength we are wont to associate with things primitive, with wild animals, and the creatures we imagine our tree-dwelling prototypes to have been—a strength savage, ferocious, alive in itself, the essence of life in that it is the potency of motion, the elemental stuff itself out of which the many forms of life have been moulded; in short, that which writhes in the body of a snake when the head is cut off, and the snake, as a snake, is dead ...

Schopenhauer's will to live:

Without moving and being part of the yeast there would be no hopelessness.  But,—and there it is,—we want to live and move, though we have no reason to, because it happens that it is the nature of life to live and move, to want to live and move.  If it were not for this, life would be dead.  It is because of this life that is in you that you dream of your immortality. The life that is in you is alive and wants to go on being alive for ever.  Bah!  An eternity of piggishness!