Is it possible to hit an incorporeal creature with a spell that requires a melee touch attack without the use of any magical ability that allows one to make contact with incorporeal beings? Put another way, does using a melee touch attack spell grant the innate ability to hit incorporeal beings with it?
The most typical example would be the use of a Cure Spell, or potentially the Lay on Hands supernatural ability, as used on incorporeal undead such as Shadows or Banshees (Undead and Incorporeal tend to go together more than any other monster type, and all undead, physical or otherwise are harmed by healing magic). Would attempting to cast a healing spell on such a creature using only your bare hands be possible? I see three possible interpretation, with two possible answers:
1) Yes, because a magic spell is being used, and all magic grants the innate ability to bypass incorporeal creatures as per its definition.
2) No, because in order deliver a spell as a melee touch attack, one must first make the touch attack, which is impossible on such a creature. The magical nature of the attack does not come into play until after the mundane contact is made.
3) Yes, because even though #2 is true, one can release the spell simply in the general vicinity of the creature (such as sticking one's hand through them and releasing it inside them) without having to strictly feel the target.
The only reason this comes up is because I am concerned that the second one is correct - that such an attack is impossible because delivering such a touch attack does not count as magical until after it hits, which it never will.