The dinosaurs have not disappeared. Every time you hear a bird sing, you hear one of their descendants. Over long eons of time, your descendants may no longer resemble you. They may have evolved into a new species, while you may be gone, as well as your own species.

In “The Fate of the Earth”, Jonathan Schell wrote at length about “the second death”, namely human extinction. He was writing about the consequences of nuclear war, but others have evoked this concept in connection with environmental disasters or unstoppable plagues.

Giving these notions further thought, it seems that there are seven kinds of death, each with an increasingly greater scope.

1. Individual or personal death, but leaving descendants in one’s own children. This ensures continuity in time.
2. Individual or personal death without leaving descendants. This means a mini-extinction of that particular branch of the family – a dead end in a family tree, which may continue to grow around the dead branch.
3. Death of a whole family tree, in one direction, though the relatives of in-laws may continue.
4. Death of a whole isolated locality, which includes the in-laws’ family trees as well. But isolated localities are quite rare
5. Extinction of all of humanity, as visualized by Schell. However, before that event, a new species — call it Son of Man — may have evolved, and is continuing. This is analogous to the dinosaur-bird situation. Such a death would still not be final.
6. Human extinction without leaving a descendant species. This is almost certainly final. Even if the evolutionary tape is rewound, Stephen J. Gould (1989) argues that it would never run the same.
7. Extinction of all life on Earth, which John Somerville called omnicide. Then there is no hope of ever re-starting, probably.

But life on other planets? Oh shush, Blind Hope, will you never stop plucking the one remaining string on your broken lyre?