Dr. Auriel ibn Michell from El Paso,Texas wrote:
I am curious about the concept of tzimtzum in the creation of the physical/spiritual universe. If G-d can constrict Himself to make room for creation, why can He not also use the same concept to become a man, a rock, or an angel?
Dear Dr. Auriel ibn Michell,
Your question is based on understanding tzimtzum to mean constricting, that G-d drew inward and made room for the universe. Unfortunately this is a common misconception.
Rabbi Chaim Volozhiner, in his book Nefesh Hachayim, specifically states that this is not the meaning in our context of tzimtzum; rather it means "hiding." He cites examples where the word tzimtzum means hidden and hiding.
The idea is that from G-d's vantage point, nothing exists besides G-d, and nothing can exist, because He must will it into existence. So in essence everything is just a manifestation of G-d. I imagine it as if the characters in your dreams would perceive themselves as real. Tzimtzum is a hiding of G-d that enables a creation that "feels" as if it has an independent existence.
The Nefesh Hachayim states that we cannot, and should not, try to delve into understanding the nature of tzimtzum, or G-d before tzimtzum.
This is an example of how studying books of kabbala can cause harm. Kabbala is easily misunderstood, which can lead to believing in a corporeal G-d. It can bring a person to not performing mitzvot if he understands that we do not really exist and the whole Torah is just a hiding of the "real" reality. Or it can be taken to the other extreme, that if G-d is equal everywhere, as in before Tzimtzum, then there can be no difference between holy and unholy things and places, because all existence is really G-d himself. This can lead people to incorrect behavior, as Rabbi Chaim Volozhiner bemoans in his work.