Recently I wrote a little about ethicist Derek Parfit.
I've been doing further research on him since, and will now describe his Big Picture as I've come to understand it.
Parfit believes that the western world only started taking ethical philosophy seriously (as a domain separate from theology) around the time Nietzsche declared that God was dead. There are only three possibilities, in terms of the God/morality issue:
1) You believe that God exists and that His commands define morality
2) You deny that God exists and, like Nietzsche, infer from this that in the absence of commands there is no right or wrong, or
3) You deny that God exists yet persist in believing and attempting to discern right and wrong.
From a certain point of view there could be a fourth category, for people who believe that God exists but that His existence is irrelevant to morality, He doesn't issue commands at all, etc. Still, from DP's perspective that sort of God is equivalent to No-God, and someone who holds to the existence of such a God must still fall into either (2) or (3) above.
Parfit places himself in category (3). But he finds himself in the company there of a lot of thinkers who see morality as "inter-subjective." I have my subjectivity, you have yours, we have to work together so we build bridges, and an inter-subjective, still not-quite objective, morality ensues. Parfit sees the work of John Rawls as typical of that approach. It is still what he calls as "subjective theory about reasons" in the passage I'm about to quote.
If that is 3(a), Parfit is 3(b). H sees 3(a) as uncomfortably close to 2.
With that much context offered, I believe I'll give him this platform to say something. The floor is yours, DP.
"If we want some event as an end, but this event's intrinsic features give us strongly decisive reasons to want this event not to occur, our wanting this event is contrary to reason, and irrational. It would be irrational, for example, to prefer to have one hour of agony tomorrow rather than one minute of slight pain later today. These claims may seem too obvious to be worth making. But such claims are denied by some great philosophers, and they cannot be made by those who accept subjective theories about reasons."