Arguments for previous necessity and their assessment

The law of 'previous necessity' known among Muslim philosophers as 'that which is not made necessary will not be brought into existence' is a sort of 'necessity by something else'. According to Muslim philosophers an effect will not be brought into existence unless it is made necessary. In other words, when a complete cause comes the effect will be firstly made necessary and then brought into existence. This law is also known as philosophical determinism. To safeguard an agent's free will, theologians have negated the necessity by something else suggesting that 'priority' is enough. They assume that with the coming into being of a complete cause the priority will lie with the existence of its effect, though its existence is not yet a must. They believe that free will will be void if the effect is necessitated by its complete cause. In other words, theologians are of the view that the law 'that which is not made necessary will not be brought into existence' implies the negation of free will. Distinguishing between a free and compelled agent, some scholars of the principles of Shiite jurisprudence have suggested that the law is applicable only to compelled agents. From among the contemporaries, it is professor Fayyazi who being strongly opposed to causal necessity presents arguments against it. Following a comprehensive approach, this article tries to find out the origin of the belief in this law through evaluating the arguments presented for it.