I don’t know. He may just mean that he’s a transhumanist - that he believes that, eventually, we’ll get to the point where people can live forever (or, at least, until the heat death of the universe).
Some pirates achieved immortality by great deeds of cruelty or derring-do. Some achieved immortality by amassing great wealth. But the captain had long ago decided that he would, on the whole, prefer to achieve immortality by not dying.
― Terry Pratchett, The Colour of Magic
