Barbarians do have a rage powers that gives them vigor and fast healing.
So, following this lead I found the following ability on the PF srd site (from the Ultimate Combat supplement, I think):
Regenerative Vigor (Ex)
Prerequisite: Barbarian 6, renewed vigor rage power
Benefit: After using her renewed vigor rage power until her current rage ends, the barbarian gains fast healing 1 for every 6 barbarian levels she has (maximum fast healing 3). She regains hit points from fast healing at the start of each of her turns.
This power uses the word "regenerative", which is an adjectival form of "regeneration", in its name. It is labelled as EX, which means that it is non-magical. And it confers fast healing. Both terminologically, and in mechanical effect, it is virtually indistinguishable from Boundless Endurance.
For those PF players who take the view that regeneration means knitting together damaged tissue, is that what this "regenerative vigour" involves? And if that is possible, non-magically, in PF world, why is it impossible in 4e world?
[MENTION=91812]ForeverSlayer[/MENTION] and [MENTION=48965]Imaro[/MENTION], is this power actually magical despite being labelled non-magical by its authors?
every example of damage being dealt in this definition is physical injury... That makes it kind of hard to take seriously any claims that damage is purely the subtraction of hit points, especially since you yourself have claimed the fiction matters...
Here's another excerpt from the dying and death defintion of the compendium...
<snip>
This is just to re-affirm the fact that your character actually dies... not stops fighting or looses the correct pacing or whatever from hit point loss... How is this possible if they are in no part a representation of physical injury to the character?
<snip>
no one argued any edition of D&D has general death spiral or debilitation mechanics and that fact has no bearing on whether damage and the resulting hit point loss is tied to physical injury.
Damage is described in 4e, at the very least in part, as physical injury (see the above examples)... so if one is physically injured then one takes damage and that physical injury is, again at least in part, represented by missing hit points...
Now, if you are able to heal hit points to the point that you are no longer missing any you are, for the third time...at least in part, healing physical injury.
This is all non-sequitur. Except in the case of the claim about the irrelevance of the absence of death spirals, which is just false.
Here is an analogy. A person who runs out of money, and who can't pay his/her bills, is insolvent. A consequence of insolvency is bankruptcy. But that doesn't mean that money is a measure of or representation of your solvency (accountants can create such representations, but at that point we're not just talking about your money). Nor that every time you spend money it's useful to think of that as moving up and down on a scale towards bankruptcy. Money is not "solvency points" or "staving off bankruptcy points".
Hit point's in 4e are, as the game rules indicate, a measure of verve and endurance. As verve and endurance are lost, so are hit points. As verve and endurance are regained, so are hit points. One way to lose verve and endurance is to be injured, but there is no rule in the game that correlates severity of injury to loss of verve and endurance (eg some characters, especially certain NPCs, may have so little verve and endurance that even the lightest injury incapacitates them, while other characters, especially PCs, may be able to sustain quite serious injuries while retaining verve and endurance). Furthermore, even if suffering an injury causes me to lose verve and endurance, I can recover that verve and endurance without healing the injury. (This is the whole premise of the absence of a death spiral in D&D.)
Finally, if you look at the descriptions of the "injuries" in the ongoing damage passage, they are all rather abstracted and don't refer to debilitation other than by way of pain: non-fatal, non-performance-impeding burns, or poison, or a "plague chant" (whatever exactly that is - something that magically corrupts the flesh, I'm guessing). There is no reference, for instance, to severed limbs, damaged organs, or other injuries that can't be overcome by any degree of verve and endurance. I regard that as deliberate. It is consistent with the overall hit point model.
TL;DR: a fighter who regenerates hit points lost to plague chant or ongoing fire damage is not magically healing damage flesh. S/he is fighting on despite the damage, with renewed verve and vigour. Much like the AD&D fighter who fights on unimpeded despite having lost all but 1 of his/her 80-odd hit points.