If we cast ourselves in imagination back before the beginning of our own existence, we enter the periods of pre-natal (or, more precisely, pre-foetal, since even the foetus forms a kind of >Proto-Self) non-existence. And if we look forward far enough into the future, we find ourselves dealing with our own posthumous non-existence. No qualitative differences can be distinguished within the non-existence of an entity x. Non-being knows no nuance or gradation. This being the case, the mere reminder that we once were not – that is, of our prenatal non-existence – should be an effective way of relieving us of all worry about our inevitable eventual death: “you” will become merely what you once were: non-existent, nothing. Since my non-existence is nothing that concerns me myself (since, at the time at which it comes to effect anything, “I” will not be, as Epicurus teaches us) the more correct way of speaking would be: a world which existed, for billions of years, without me in it was succeeded, for a few decades, by a world with me, which world will then in its turn be succeeded by a world which will go on existing, for more billions of years, without me. If there is nothing frightful in a prenatal non-existence which endured for many aeons (see, however, >the Fear of Having Never Been), why should there be anything frightful in an eternally enduring non-existence after death?
Lucretius attempted to justify, by reference to this absolutely equal value of prenatal and posthumous non-existence, an unconcernedness in the face of death. But this “consolation of philosophy” does not work; it remains a bitter medicine. Because what concerns us most of all is not the “me”-less world that precedes and succeeds the time of our existence but rather the fact of having to die: the fact that, in our dying, something beyond our comprehension will befall us. We have to do here with an event of which we assume that it cannot possibly be “practiced” in advance (although we do in fact, each time we fall into a dreamless sleep, anticipate death in its essence and it is demonstrated to us, each time we reawaken from such a dreamless >Sleep, how “it” was not to have existed for a few hours at a time). The reason why we fear our impending non-existence more than we do the non-existence that lies behind us may well be rooted in the simple fact that, however much we reflect, we cannot rid ourselves of the idea that something will befall us at the end of our lives (that we will have to suffer through the actual process of dying) and that we will undergo something very unpleasant before the world becomes once again a “world without us”.
Whereas the reference to “going to sleep” is an impotent attempt at appeasement with regard to the actual process of dying, the following is an attempt to soothe our fears in respect of our impending non-existence: with our death it is being that becomes ontically “poorer”; we ourselves are not affected by it; likewise, with the beginning of our existence it was being that became ontically “richer”; we ourselves did not become richer or gain anything thereby. Death subtracts us from that remaining part of being to which we were added with the beginning of our existence. The beginning and end of our existence are things that befall not us ourselves but rather the being that surrounds and bears us. As embodied consciousnesses we fall over and over again into the “error” of seeing the beginning of our existence as a gift that was given to us and our death as a loss which befalls us ourselves. Being mind-endowed entities whose existence, nonetheless, rests firmly upon the persistence of our physical organisms, it is inevitable that we have, as it were, “a taste for being” and that we are subjected to the tyranny of the body (>Bionomic Principle). Where IT is and bionomically raises its claims, it is only with the greatest difficulty that I can assert myself and have my way. These observations throw a harsh, clear light on how justified is the description of >Suicide Cynicism for remarks of the kind: ‘whoever is not satisfied with life is free to send him- or herself- back into the condition they were in before they began to exist”.
These matters were also reflected upon by Friedrich Theodor Vischer in his book Auch Einer: eine Reisebekanntschaft, namely in the following way: “Whoever is made unhappy by the thought that, after his death, he will no longer be alive needs to be reminded of the demands of logical consistency. No one ever feels unhappy over the fact that it was only at a certain point that he began to live, that is to say, that before his birth he was not alive; he should be no whit more unhappy, then, over the fact that he will at a certain point cease to live. Admittedly, one great difference exists here: in the meantime, the individual in question will have become accustomed to life – and life, as is well known, is a dish that is decidedly ‘more-ish’!” (Vischer, Auch Einer. On the asymmetry between our attitudes respectively to past and to future non-existence, see also Nagel, The View from Nowhere)
 Or rather, to speak more precisely: that before the beginning of his existence he was not alive.