Many find the Epicurean reasoning about death sophistical. Among those who do, we encounter some strange bedfellows. To compress the famous reasoning into a trio of sentences:
When we are, death is not. When death is, we are not. Therefore, death is nothing to us, and nothing to fear.
The distinguished German Thomist, Josef Pieper, in his Death and Immortality (Herder and Herder, 1969, orig. publ. in 1968 under the title Tod und Unsterblichkeit) speaks of
. . . a deception which men have long employed, particularly in classical antiquity, in the attempt to overcome the fear of death. I refer to the sophism of not encountering death, which Epicurus seems to have been the first to formulate; "Death is nothing to us; for as long as we are, death is not here; and when death is here, we no longer are. Therefore it is nothing to the living or the dead." [In footnote 13, p. 134, Pieper reports, "Ernst Bloch, too, has recently repeated the old sophism. Das Prinzip der Hoffnung, Frankfurt a. M., 1969, p. 1391] The same argument, or variations of it, has been repeated many times since, from Lucretius and Cicero to Montaigne and Ernst Bloch; but the idea has not thereby become more credible. (p. 29)
Why does Pieper consider the Epicurean philosopheme to be a sophism?
What Epicurus attempts to do is to quarantine death, restricting it to the future period when when we will be dead and presumably nonexistent. Or perhaps we can say that Epicurus is engaged in an illicit compartmentalization: there is being alive and there is being dead and the two compartments are insulated from each other. Thus when we are alive we are wholly alive and death is nothing to us. And when we are dead, death is also nothing to us because we no longer exist.
I read Pieper as maintaining that this is a false separation: death is not wholly other than life; it is a part of life. We are not wholly alive when we are alive. Rather, we are dying at every moment. Compare Benatar for whom death is part of life in that "death [being dead] is an evil and thus part of the human predicament." (The Human Predicament, p. 110) Part of what makes the human predicament bad is that death awaits us all as a matter of nomological necessity. Now Pieper would never say that the human condition is bad or evil, believing as he does that the world is the creation of an all-good God; but the two thinkers seem agreed on the following precise point: death cannot be assigned to the future in such a way that it is nothing to us here and now.
For Pieper, the image of death as Grim Reaper, although apt in one way, is misleading in another, suggesting as it does that death is wholly external to us, attacking us from without and cutting us down. Of course it is true that our lives are threatened from without by diseases, natural disasters, wild animals, and other humans. To this extent death is like a scythe wielded from without that cuts us down. But it is not as if we would continue to live indefinitely if not attacked from without. Death does not kill a man the way his murderer kills him. What images such as that of the Grim Reaper hide, according to Pieper, is the fact
. . . that we ourselves, in living our life away, are on the way to death; that death ripens like a fruit within us; that we begin to die as soon as we are born; that this mortal life moves towards its end from within, and that death is the foregone conclusion of our life here. (28)
If so, then death cannot be pushed off into the future where it will be nothing to us. It is something to us now in that we are now, all of us, dying. While alive we are yet mortal: subject to death. But not in the sense that it is possible that we die, or probable, but in the sense that it is necessary. To be mortal is to be potentially dead, and living is the gradual actualization of this potentiality. Death would be nothing to us while we are alive if we were non-mortal until death overtakes us. But this is not the case: we are mortal while we are alive. We don't go from being wholly alive to wholly dead; we go from being potentially dead to actually dead.
The Epicurean therapeutics is supposed to allay our fear of being dead, and to some extent it does, on the assumption that we are wholly mortal. But it does nothing to allay our anxiety over being mortal. Being mortal, and knowing that I am, I know what is coming, my personal obliteration.