It is obvious that effects depend upon causes, but causes also, in a subtle sense, depend upon effects. Every cause itself is an effect of its own causes, which preceded it, and therefore arises in dependence upon its respective causes…effects arise in dependence upon causes. Here cause and effect are in a temporal sequence, an effect occurring after its cause.
Because the designation of something as a “cause” depends upon consideration of its effect, in this sense a cause depends upon its effect. Something is not a cause in and of itself; it is named a “cause” in relation to its effect. Here the effect does not occur before its cause, and its cause does not come into being after its effect; it is in thinking of its future effect that we designate something as a cause.
Agent and action depend upon each other. An action is posited in dependence upon an agent, and an agent is posited in dependence upon an action. An action arises in dependence upon an agent, and an agent arises in dependence upon an action. Nevertheless, they are not related in the same way as cause and effect, since the one is not produced before the other.
How is it that, in general, things are relative?
How is it that a cause is relative to its effect?
It is because it is not established in and of itself. If that were the case, a cause would not need to depend on its effect. But there is no self-sufficient cause, which is why we do not find anything in and of itself when we analytically examine a cause, despite its appearance to our everyday mind that each thing has its own self-contained being.
Because things are under the influence of something other than themselves, the designation of something as a cause necessarily depends upon consideration of its effect.
—Tenzin Gyatso, the 14th Dalai Lama