Shaar HaGilgulim

כדכתיב: החכמה תחיה בעליה

as it is written,7 “Wisdom gives life to those who possess it” — the soul, which possesses the faculty of wisdom, receives its life by means of this faculty, as stated above.

ולפעמים ממשיכים פושעי ישראל נשמות גבוהות מאד שהיו בעמקי הקליפות, כמו שכתוב בספר גלגולים

Does the soul come back in a new born body?

Yes, but not always, and most times in parts...

In order to understand the process of reincarnation, one must first comprehend the anatomy of the soul as it relates to the Sefirot, the souls emotions aka the divine attributes.

The soul contains 5 level, listed from "lowest" to "highest":

- Nefesh

- Ruach

- Neshama

- Chaya

- Yechida

to be continued...i'y'h