What is good and what is bad? I know of no physics based definition of the concept, much less a universal constant, and there does not appear to be any such thing.
Or if you prefer that I not only have the word of the [deity] available to me but have actually read them and dismissed it as so much ancient bullshit means I am a thoroughly wicked dude in the eyes of some (better yet for the sake of argument I will make myself an apostate), for others it just means I am a rational human being and for them then being rational is a human ideal (humanity has rapidly changed since we left the savannahs however many millennia ago, far faster than biology can keep up with and for now at least technology has not offered a solution as much as a glimpse at some and paths to them).
To that end good and bad stem from morals which are a human invention*, albeit ones with a basis in biology** and selected for over many many many generations.
*there are people that would claim that morals are divinely inspired/mandated and are very ardent in this belief.
**I am presumably descended from ones which checked behind the bush for a snake/lion/bear, shared with their community enough that they weren't booted out and so forth.
In psychology then often the easiest way to start understanding something is to look for the damaged, the aberrations and things on the extremes. As such then killing another human seems to be a near universally reviled concept so we can start with that
Stats vary a bit but before conditioning was invented (and if a news story here was anything to go by might well be disinvented before long for stupid reasons) some note it lines up rather well with estimates of sociopathy, though there appear to be exceptions even there (such things then becoming acts of heroism, self sacrifice or "I just wanted to get everybody home"). It has also long been recognised that making said killing a bit more abstract makes it easier in psychological terms as well as practical ones (give or take training).
Some others in the thread described what might be known as either sociopathy or psychopathy, however in and of themselves I don't know that such things are bad. You can have high functioning sociopaths, indeed it is observed that many politicians and business types might be this -- far easier to take the risks if you don't care about your employees having to get new jobs, or start wars if you don't have to think about all the death and destruction that will come with it*.
*I was recently looking into the German side of the North Africa campaign in world war 2. I forget the exact names and ranks but one had to fire one of his subordinates, a line noted was something along the lines of "you think too much about the well being of your men" (in military terms it is tactics vs strategy, tactics in battles (if being shot at then duck), strategy wins wars/campaigns) and the guy came back and said "I can think of no higher praise".
Sociopaths seem to be born, raised or created through illness and injury and I can believe other variations on the theme exist ("give them to me young enough" and all that). To that end I can well believe there are people supremely suited to acting within a given moral framework, and those that can scarcely understand the concept for it (
https://tvtropes.org/pmwiki/pmwiki.php/Main/BlueAndOrangeMorality covers it in a less washy means), or at least are terribly unsuited to operating within it. How moral is your moral framework -- to me the notion that you may kill, shun or otherwise really mess stuff up for an apostate is repulsive, horrific and various other related words, and I have gone out of my way to help some that suffered it in the past and happily condone efforts to undermine places and groups where it happens.
