A Geiger counter will pick up whether an item has been near uranium.
So? The point is that not everything is capable of detecting anything at any trace level, no matter how small. The concept of a minimal detection limit is quite real.
Why must a geiger counter be the correct analog? Obviously the rules indicate that my nose is a better analog.
If that's the game reality you want. If you want a spell that can detect when an otherwise and generally neutral 6 HD rogue has decided to act on evil intent, but cannot detect a 3 HD goblin leader who has personally murdered dozens of individuals, some of them just for sport, over the course of years, then I guess the spell functions correctly for you.
I don't have one correct answer. This answer works for me, as did 3.5.
Since this is a change from 3.5, I want to know, "What does this do better?" And I am not especially interested in hearing about particles of Evil Radiation, since that is certainly not a part of many game worlds.
Really? Because my 3.5 PH talks about "Aura Power". And the power of an aura changes with HD. This change in power is the only thing I am talking about. Why does an 11HD evil rogue show up differently than a 10HD evil Rogue under 3.5 rules? The answer is that his evil aura radiates more powerfully than 10 HD rogues. According to 3.5 the amount of whatever is being detected is increased as HD go up.
I think this is your underlying problem. You are imposing a false interpretation of the mechanic and demanding that everyone agree with you. Not only do I disagree, I believe your model flies in the face of 3.5. 3.5 requires that there be some sliding scale of both magnitude of evil aura and that the response of detect evil varies with this magnitude.
You do not have to believe in evil; it believes in you.
True, and unless there is enough of that evil, Detect Evil can not find it, regardless of who believes in what.
Given that, the inability of the spell to detect even a faint amount of evil on a very evil creature, simply because they lack experience or notable life accomplishments, seems illogical.
That is not given.
In a world where Evil is a force of nature, I don't see how having an evil alignment can ever be trivial.
The potential for that evil to do anything about it can be very very trivial. But that aside, no one is saying the evil is trivial, only that a L1 spell can not detect it. It could be REALLY serious deadly horrid evil and not be detectable by this first level spell. There is not contradiction there. You are related two unrelated items.
I think what it does better is creates a lot more shades of gray in terms of what Detect Evil says. I think it is a good thing. It isn't one of the changes that I'm singing the praises of. I wouldn't cry if it was not changed. But it is better than before.
I don't see the slightest lack of logic in the position.
Why were you ok with a 3.5 evil showing less clearly if it had 10 HD than 11 HD? (And didn't this commit the sin of letting a PC grok the difference between 10 and 11 HD, thus knowing that HD exist?)
If evil can have different tiers of "aura power" then it is totally rational that different detection techniques could have different capacity to detect these tiers. I would have no issue whatsoever with an item or spell that only detected Overwhelming auras, or strong+ auras, or moderate+ auras. To an item that could not detect anything less than strong, there would be no functional distinction between "moderate" and "none". That doesn't mean the aura is not there, only that the detection can not perceive it.
And this type of situation does exist over and over in the real world. There is no requirement that Detect Evil work like real world detection devices. But neither is there any requirement that it contradict real world systems.
I am an environmental engineer. I deal with analytical data constantly. It is very common for me to look at water data that has been tested for benzene, for example. I will never ever get a result that says there was no benzene in the water. That answer is not possible. A typical "not detected" result is < 1 microgram per liter. It may be that there truly was not a single molecule of benzene in the sample. But it also may be that there was 0.868 micrograms of benzene in every liter of water present. That I deal with reporting limits all the time may be part of why I find it so easy to wrap my head around a less than reported positive value.
I have not seen anything that says why evil must be detectable down to infinitesimal levels. If anything, following you argument to its logical conclusion should say that aura power should not exist and detect evil is an up/down yes/no for anything and everything.