The Law of Compensation is that the swing in one direction determines the swing in the opposite direction, or to the opposite pole–the one balances, or counterbalances, the other.

On the Physical Plane we see many examples of this Law. The pendulum of the clock swings a certain distance to the right, and then an equal distance to the left. The seasons  balance each other in the same way. The tides follow the same Law. And the same Law is  manifested in all the phenomena of Rhythm. The pendulum, with a short swing in one direction, has but a short swing in the other; while the long swing to the right invariably means the long swing to the left.

An object hurled upward to a certain height has an equal  distance to traverse on its return. The force with which a projectile is sent upward a mile is  reproduced when the projectile returns to the earth on its return journey. This Law is  constant on the Physical Plane, as reference to the standard authorities will show you. But the Hermetists carry it still further. They teach that a man’s mental states are subject to the same Law. The man who enjoys keenly, is subject to keen suffering; while he who feels but little pain is capable of feeling but little joy.

There are temperaments which permit of but low degrees of enjoyment, and equally low degrees of suffering; while there are others which permit the most intense enjoyment, but also the most intense suffering. The rule is that the capacity for pain and pleasure, in each individual, are balanced. The Law of compensation is in full operation here. But the Hermeticists go still further in this matter. They teach that before one is able to enjoy a certain degree of pleasure, he must have swung as far, proportionately, toward the other pole of feeling.

They hold, however, that the Negative is precedent to the Positive in this matter, that is to say that in experiencing a certain degree of pleasure it does not follow  that he will have to “pay up for it” with a corresponding degree of pain; on the contrary, the  pleasure is the Rhythmic swing, according to the Law of Compensation, for a degree of pain previously experienced either in the present life, or in a previous incarnation. This throws a new light on the Problem of Pain.

The Kybalion