[Spells help] feeblemind                                                     

Syntax: cast 'feeblemind'                                            

While the necromancer is well known for creating zombies from the
corpses of the dead, feeblemind is able to turn the minds of the
living into those of zombies (for a time).  The victim of this spell
will find him or herself unable to think clearly for a time.

Feeblemind also directly counters the insight spell (and vice versa).

See also: insight