Answer: It is true that development never flows evenly and in a linear fashion, there are always spurts. This is the way it manifests in our sensations because of the flaws in our work, and it will continue this way until the final correction. Good and bad periods alternate, war and peace replace one another, and we keep experiencing sudden changes. Periodicity is an inherent aspect of development.
The same applies to the structure of the Partzuf which divides into five degrees of Aviut (the depth of the desire). There is a screen and a Light on every degree; they are organized discretely and consecutively, not linearly. Everything comes in portions and drops, it does not flow evenly. This is why periods can sometimes be positive and sometimes negative; they need to be used differently. We learn this from our own experience.
From the Talk On Unity in the Group 9/24/10
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