Attempted answer: the Tzimtzum allows the two opposites of Havaya and Elokim (Ohr and Keli, Guf and Neshama etc.) to meet altogether.

Page 24- 5. When one meditates on the aforementioned צמצומים that allow for creation to exist [one can react by focusing on themselves and the sustaining of the צמצום or] one reacts by wanting the truth, rather than the צמצום. In this מאמר he desires the entire truth. Three [or four] levels: A) שכינה the…

Class One. The Hemshech continues. The Ma’amar wishes to explain Tzimtzum to us, so we will understand the significance of reversing it in revealing Godliness in the ‘space’ of the Tzimtzum when Moshiach comes. To explain this he begins (indirectly, by) discussing what is ‘before’ (Godliness is simple and worldliness must be learned) and ‘after’…