"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents." - H. P. Lovecraft, The Call of Cthulhu

It's interesting to see how prevalent death is in the ethical literature. Off the top of my head, there's:

• the various incarnation of the Trolley problem (at least one person dies)
• the debate about abortion and the legality of killing a fetus
• the ethics of killing animals, whether that be for sport, entertainment, cuisine, etc.
• the ongoing debates on immigration policy (which oftentimes decide whether or not refugees will die)
• the possibility of a just war (in which combatants and/or civilians will be killed)
• the permissibility (or lack thereof) of the death penalty
• the limits of self-defense (whether or not it is acceptable to kill someone to defend yourself)

This is not an exhaustive list. Death is strikingly prominent in ethical discourse.

What is also prominent and intuitively obvious is that pain seems to be more important than pleasure. I have made previous posts here on this before; pain is prima facie of ethical priority.

From a biological, evolutionary perspective, pain is a subconscious adverbialist orientation towards a certain kind of stimulus: notably tissue damage. What we feel as "pain" is the command to "GTFO NOW" - in other words, any experience of pain can be described as essentially the wish to cease experiencing certain stimuli - to "disapprove" of stimuli as a subconscious motivational complex.

The opposite can plausibly be said of pleasure: pleasure is a subconscious adverbialist orientation towards a stimulus: notably the satisfaction of concerns. Concerns come in a wide variety but can be more or less reduced to two (overlapping) kinds: needs and desires. The experience of pleasure can then be described as essentially the wish to continue to experience certain stimuli - to "approve" of stimuli as a subconscious motivational complex.

Because of pain's inherent connection to tissue damage, and because of tissue damage's inherent connection to the morality of the organism, it stands that pain is inherently connected to death (and pleasure inherently connected to life). What is painful is what puts the organism at risk, and what is pleasurable is what puts the organism in reassurance and stability.

However, all systems are entropic, and therefore predisposed to fatigue. In biological systems, this results in inevitable death. From the very moment of conception, we are in a state of decay - a metaphysical directedness-towards-annihilation (pace Heidegger).

As so much psychological, anthropological, and even philosophical data has shown, humans have an innate fear of death and a drive to continue to exist. The fear of death coincides with pain (which coincides with death), and the drive for persistence coincides with pleasures (which coincides with life).

In fact, it's impossible to experience pleasure, comfort, or be generally happy during the moments when one fully understands ones mortality. Consciousness - the ego - cannot imagine it's own non-existence. This was picked up by thinkers like Freud, Becker, Zapffe, Lovecraft, and others.

"Illusions commend themselves to us because they save us pain and allow us to enjoy pleasure instead. We must therefore accept it without complaint when they sometimes collide with a bit of reality against which they are dashed to pieces." - Sigmund Freud

Therefore, is stands that pleasure, in relation to our metaphysical fatalism, is misleading, whereas pain is enlightening. Pleasure is misleading because it puts our guard down against death (since we cannot experience pleasure while simultaneously fully understanding the extent of our mortality) - in the phenomenological sense, it is almost certainly intoxicating (we are "addicted" to pleasurable feelings, no question about that). Pain is enlightening because it reminds us of our mortality.

This is perhaps one of the main reasons why we place pain on a higher priority than pleasure in ethics: because we are inherently fearful of death, and pain reminds us of our own immanent mortality. Which is also why death is so prominent in ethics. We are surrounded by it.