There's a story about R' Zusha and R' Elimelech (two famous Hasidic brothers and Rebbes) going to ask the Maggid (of Mezritch, their teacher and mentor) a very profound question:I love this story for a number of reasons, maybe most of all is the pure simplicity of R' Zusha and R' Elimelech in their certainty that Adam could not have sinned if they were in any way part of Adam. Now, I trust this story because of the holy chutzpah it contains, but I'd never seen Kabbalistic or Hasidic support for it until now.
Rebbe, it is taught that Adam contained the souls of all of Bnei Yisrael. If this is so, then we were there too. If we were there, part of Adam, we never would have let him sin, so how is it possible that he sinned?
The Maggid replied: Before the sin, a number of holy souls fled his body and only then was he able to sin, you were among those souls.
The Ben Ish Hai on this week's parashah (Tetzaveh) explains that the Tzitz hints at the entirety of the souls of the Jewish people. The first Tzadi represents the 90 (gematria of צ) souls that left Adam before the sin, the Yud represents the 10 which remained, and the final Tzadi represents the 900 (the gematria of tzadi sofit) souls that fell into the klippot and must be redeemed.
So finally the story has some corroboration I'm happy to say. (Obviously if I'd learned any serious amount of the teachings of the Ariz"l, which I haven't, I would've probably already learned the source of this idea.)