Our Sorcerer was hit by massive Int drain, to the point that she had an effective Int of 2. Between then and the time we could fix her Int drain, could she cast spells?
There are two obvious factors:
To cast a spell, you must be able to speak (if the spell has a verbal component)…
Having a low Intelligence means that you can't understand language:
Creatures of animal-level instinct have Intelligence scores of 1 or 2. Any creature capable of understanding speech has a score of at least 3.
Thus, she would not understand the words necessary to fulfil the verbal components of her spells.
However, the Sorcerer:
can cast any spell she knows without preparing it ahead of time. To learn or cast a spell, a sorcerer must have a Charisma score equal to at least 10 + the spell level.
Thus, the verbal components need not necessarily be intelligible speech, just words that "feel right" for the spell (borrowing from the Dresden-verse a bit). And, while she didn't understand language, she still had all of the physical equipment to produce language's sounds.
Tactics, targeting, etc. aside, do RAW speak specifically to an extremely-low Int spontaneous caster's ability to cast?
Best Answer
Probably yes, a sorcerer with an Intelligence score of 2 yet possessing sufficient Charisma can still cast spells with verbal components
The GM can rule that a low-Intelligence sorcerer can't cast spells, but the game doesn't outright say such a sorcerer can't cast his spells. Therefore, ultimately, the GM must decide. That's because according to Components
While Pathfinder has several sets of rules for things called incantations (e.g. here, here), the term incantation as mentioned in Components is undefined, so the GM can then consult his favorite dictionary and use that definition of incantation to tell the sorcerer player No spellcasting for you.
Further, the GM may rule that the sorcerer's low Intelligence score makes him incapable of verbalizing at all, dropping the poor sorcerer back to the prelinguistic stage of language development.
But, assuming that the GM doesn't want to player to head off to the other room and play Smash Bros. until the sorcerer's Intelligence is at least 3 and that the player appreciates the challenge of role-playing, essentially, a dog with a built-in shotgun, the DM should permit the low-Intelligence sorcerer to cast spells.
Note that I would be very wary around a dog with a built-in shotgun, especially if that shotgun were reloaded automatically each time the dog wakes up from a long nap. I'd go to great lengths to keep that dog fed, happy, safe, and appropriately amused.
Because it's been referenced in several Comments, in Pathfinder's antecedent Dungeons and Dragons 3.5, under Monsters as Races it says
Then, later under Ability Scores for Monster PCs, it says
Neither artifact, so far as I can tell, appears in Pathfinder.