and circular dependence involving disparity. For it is impossible for each of two things to be the cause of the other, since a cause precedes its effect. Each would then necessarily be both the cause and the effect of the other, and would consequently precede and follow it. This would entail each preceding itself by two steps and following itself by two steps. It would also entail each being its own cause and its own effect, since it would be both the cause of its cause and the effect of its effect.

It is not impossible, however, for each of two things to coexist with the other such that neither exists without the other, as with mutually constraining relations such as fatherhood and sonship, and the like. This is circular dependence