There is no way to deny the universality of the principle of causality and cause-effect necessity just as voluntarinees of our acts cannot be denied. What Muslim philosophers, especially Mulla Sadra, have argued for the universality of the principle of causality and its necessity and their responses to the objections are sound, but further points have to be made.
1. The relation of the essence of cause to its effect is a comparative contingency, imkan-e bil-qiyas. Cause cannot be made necessary by its effect.
As explained before, the effect is nothing other than belonging to and dependence on its cause. The effect receives necessity of existence from its cause and, therefore, the relation of the essence of effect to its cause is necessity caused by the other, darurate bil-ghayr.
2. In the material world there is no real originating cause (al-‘illah al-fa‘iliyyah) that grants existence. All material causes are preparatory causes (‘illat- i‘dadi) or material causes (i.e. potentiality for existence or recipients of existence). In immaterial world all originating causes are voluntary.
3. In the immaterial world where the voluntary originating causality exists the relation of the essence of cause to the effect is that of a comparative contingency, while the relation of the effect to its originating cause is that of necessity, since the effect is nothing other than belonging to and dependence on its cause.
4. Our mind abstracts the notion of sovereignty from the mutual relation of cause and effect, which is from one side imkane bil-qiyas and from the other side darurate bil-ghayr.
Therefore, the theory of sovereignty can be somehow reduced to the above-mentioned mutual relation. According to this account, there is a special relation between a voluntary agent and its effect that is a combination of comparative contingency of the cause and necessity (caused) by the other of the effect. This very relation is the one from which notions of sovereignty and ikhtiyar are abstracted. It is also the same relation that accounts for the appropriateness of reckoning, punishment and reward.
In this way the problems raised against the theory of necessity or the theory of sovereignty as discussed above or more generally against the relation of cause and freedom can be solved. Further explanation of this point needs a separate discussion.