Although The Idiot quite plainly deals with the havoc that the arrival of an innocent man can have on an established society, in reality, the level of innocence that Myshkin displays fluctuates wildly throughout the text. Sometimes he is so clueless that he carelessly reveals what are obviously secrets, and other times he is insightful and clever enough to figure out another person's whole psyche after meeting them only once. Innocence is portrayed as a changing quality, and although many characters profess to admire Myshkin's purity of heart, there are none who would actually want to be like him.
Myshkin's particular brand of innocence manages to disarm those around him because he is male and not nearly as bound to a traditional social role. Were he a female character in the world of the novel, the same qualities would mark him as dangerously unstable.
Even though Aglaya is pitted against Nastasya as innocence versus experience, Aglaya is experienced enough to cut right to the heart of Nastasya's meddling in Aglaya and Myshkin's relationship.