And in Jewish mystical thought, specifically in texts like Kalach Pitchei Chokhmah, we find a fascinating, intricate answer.

The story starts with light, with holiness. Before anything else, there was the Eyn Sof, the Infinite, and from it emanated the Sefirot, the ten attributes or emanations through which God reveals Himself. Think of them as divine blueprints for creation. But even within this perfect system, a crack appears.

Now, Kalach Pitchei Chokhmah explains that even after the initial act of creation, a single light of holiness remained. It calls this the "Residue," a last echo of the primordial Root. But this Residue light isn't entirely without flaw. It carries a "certain deficiency." And here’s where things get interesting.

This deficiency, this imperfection within the light, is the root of the Sitra Achra, the "Other Side" – what we often understand as evil. But hold on, it's crucial to understand that this deficiency isn't on par with the light of holiness itself. It’s not a parallel branch, not an equal force. We can't say the deficiencies in the Sefirot are equivalent to the Sefirot themselves.

Why not? Because, as Kalach Pitchei Chokhmah emphasizes, these deficiencies were newly brought into being. Their purpose wasn't inherent in the original divine plan; instead, they were created specifically to serve as the root of the Other Side.

Think of it like this: the Sefirot are an extension, a branch growing directly from the primordial Root, the Eyn Sof. They are a continuation of divine goodness. But the deficiencies within them aren't extensions. They're a new root. And from this new root, the Other Side develops as its own, separate branch – a branch parallel to a branch, but not to the original trunk.

So, evil, in this view, isn't an equal and opposite force that sprung forth from the Eyn Sof itself. Instead, it emerges from a deficiency within creation, a deliberate (though mysterious) act that establishes a new origin point.

It's a complex idea, isn't it? It suggests that evil isn't inherent in God, but rather a consequence of the created world, a shadow born from the imperfections allowed to exist within the light. And perhaps, understanding this delicate balance, this precarious relationship between holiness and its shadow, is the first step in navigating the complexities of good and evil in our own lives.