Weapon Finesse & class fighting styles

When someone wields a one-handed weapon in two hands (e.g., a sword) does this eliminate the benefit of Weapon Finesse? Or is the restriction only (two-handed) weapons per se?

Also, I'm assuming that if someone can wield a weapon categorized as a two-handed weapon (such as a two-handed sword), then this also mean that she can also wield a one-handed weapon in two hands (such as a sword)? That is, if one can wield two-handed weapons, then it (logically) follows that one can wield certian one-handed weapons in two hands?

(I read a couple threads about it and the errata, but I'm still a bit confused).

Thanks!

I honestly don't know what the "official" stance on this is, but in my own campaign I went with one-handed-only weapons (e.g., short sword, dagger, whip, etc.) for Weapon Finesse.

I personally would allow the weapon finesse bonus regardless of style or weapon choice, only excluding the pure two handed weapons.
Its not really such a popular proficiency anyway.

I also allow the benefits of Weapon Finesse for anyone with a DEX bonus wielding a one-handed weapon (no shield), without the proficiency. 

It never came up, but I would negate that bonus if they used the weapon in two-hands - the increased damage die implies you're wanting to brute force a solution.

FWIW, there was some other discussion about single weapon fighting here:

http://www.autarch.co/forums/ask-autarchs/single-weapon-fighting-style-0

which talks about Fighting Style: Single Weapon a bit, which also comes up every once in a while as far as what you can hold.

 

Also, I’m assuming that if someone can wield a weapon categorized as a two-handed weapon (such as a two-handed sword), then this also mean that she can also wield a one-handed weapon in two hands (such as a sword)? That is, if one can wield two-handed weapons, then it (logically) follows that one can wield certian one-handed weapons in two hands?

To answer this question (and I, also, am not an Autarch):

Yes, you can use a one-handed weapon in two hands if you can use two-handed weapons. Or, more accurately, any class that can use two-handed weapons needs to have access to the Two Hands On A Weapon fighting style, which allows both use of strictly two-handed weapons (such as two-handed swords and greataxes) and use of one-handed weapons in two hands (like a longsword or spear for the d8 damage die).

The errata that I assume you mentioned you read is here, I link it in case others need to see it.

The Fighting value of a class will determine how many styles they have access to, and which weapons they have proficiency with specifically. Is there a specific class you were thinking of that confused you? From a class design point of view, the greater likelihood of confusion to me is that you might give proficiency with big weapons but want to trade away the 2h fighting style (which you can’t do).

Thanks! And I found the discussion in the link insightful.

It's not? It's pretty popular amongst dexterous characters that I've seen.

EDIT: We're talking about Weapon Finesse, right? I haven't seen Fighting Style: Single Weapon much.

To make Weapon Finesse a useful choice (Dex better then Str) for characted a few things have to fall in place besides Dex in my opinion :
-Good enough armor/weapon selection and HD for close combat
-Damage bonus from class and/or Str

Characters fitting that usually have strength as a prime stat and therefore are somewhat rare and in other cases its usually better in my opinion to go all out ranged combat.

Okay, I haven't found this at all. While ranged combat is a safer option, it's also a more limited option under many circumstances. Combatants can't fire into melee unless they dedicate a Class Proficiency to it (the Elven Ranger being the exception), and even if they do so the shots are still at significant penalty (-4 to hit). I've seen Weapon Finesse taken by Characters who simply don't have a Strength bonus (or have a Strength penalty) but are still capable in melee and have a Dexterity bonus. I've seen a Thief, a Spellsword, and Bladedancer all take it. The reasons they took it could be just as applicable to an Assassin, a Bard, an Elven Nightblade, or an Explorer, as a +2 to hit (i.e., 16-17 Dexterity) is equivalent to the improvement in Attack Throws from 3 Levels of Fighter! That's nothing to sneeze at.