As Zandel's post illustrates, it is possible to follow this debate for quite a while without quite "getting" what the disputed issue actually is.
That said, let me put my oar in.
SRD said:
A monk’s unarmed strike is treated both as a manufactured weapon and a natural weapon for the purpose of spells and effects that enhance or improve either manufactured weapons or natural weapons.
It seems to me there are two "effects" that are relevant to the discussion. One effect is the benefit of the INA feat. I read the FAQ clarification as stating that human monks can benefit from the INA feat. That seems straightforward, and I don't think anyone is disputing this. The issue is whether a monk's unarmed strike counts as a natural weapon for the purpose of meeting prerequisites. Whatever a prerequisite is, it does not seem to be an effect that enhances or improves a natural weapon.
The other "effect" is the INA feat itself. If it were an effect, then it would certainly (as a whole) enhance or improve a natural weapon, and so, if it were an effect, it would treat a monk as having a natural weapon. If the whole feat treats a monk as having a natural weapon, then all the parts of the feat should treat the monk as having a natural weapon. Even the prerequisites.
There are two main arguments advanced for a feat to be considered an effect. One is the prerequisite of the Improved Spell Resistance epic feat:
SRD said:
Prerequisite: Must have spell resistance from a feat, class feature, or other permanent effect.
The other argument is to say that acquiring a feat is a result (=effect) of leveling up. Since "effect" is a rather imprecise term, this may be a legitimate reading.
Consider Dimwhit's latest argument in the context of INA being an effect.
Dimwhit said:
The unarmed strike 'qualifying as a natural weapon' for an effect is the same thing as saying it 'satisfies the prerequisite for' an effect.
Patryn of Elvenshae refusal to accept this principle stems, I think, from treating the "effect" as being the first kind of effect (the benefit of the feat) and not the second kind of effect (the feat itself). After all, it is certainly possible to benefit from an ability without satisfying the prerequisites required to actually acquire the ability.
In short, I think that if the INA
has an effect that enhances a natural weapon, it does not seem that a human monk is eligible to take it. But if INA
is an effect that enhances a natural weapon, a human monk would be eligible to take it.
At the moment I tend toward the latter view, but I have the utmost respect for Patryn of Elvenshae and the other proponents of the Nay side, and would very seriously consider any objections that might be raised to this position.