What are the Zoroastrian teachings on good and evil?

Evil is one of the oldest questions a mind can ask — not just what it is, but whether it could exist without good standing opposite it. The Taoist texts say no: good and evil are twins, each summoning the other into being the moment it is named. Jewish mysticism goes further, suggesting the evil impulse is not a permanent feature of the cosmos but a scaffolding, necessary only for this age of the world and fated to be dismantled.

Drawn from 4 passages across Tao, Judaism

Do good and evil require each other to exist?

The Taoist texts make a startling observation: good and evil are not independent realities but relational ones, each called into being by the other's existence. The Kabbalistic tradition adds a wrinkle — this mutual dependency may be a feature of time itself, not of ultimate reality.

Tao

Good and evil are mutually constituted, not independent realities.

Good doesn't exist; bad doesn't exist: except through the other.

Tao

Opposites including good and evil are inseparable and ultimately undivided.

So are ugliness and beauty, greatness, wickedness, perverseness, and strangeness. Separation is the same as construction: construction is the same as destruction. Nothing is subject either to construction or to destruction.

Tao

Good is known only through contrast with its opposite.

All in the world know the beauty of the beautiful, and in doing this they have the idea of what ugliness is; they all know the skill of the skilful, and in doing this they have the idea of what the want of skill is.

What is the origin and ultimate fate of the evil impulse?

Jewish mystical teaching here is precise and striking: the evil inclination is not an eternal fixture of reality but a temporary necessity, required only for the duration of this world's six millennia — after which it ceases to be needed.

Judaism

Evil is a temporary necessity of this world's age, not an eternal reality.

The existence of the evil inclination and the Sitra Achara is only necessary during the six millennia of this world, which go according to the conduct of the six Sefirot.