This group of demonstrations has some special features...

This group of demonstrations has some special features: first, that they do not require sensory or empirical premises; second, the doubts and misgivings which surround the other arguments have no way here, and in other words, they have greater logical validity; and third, the premises of these demonstrations are also more or less needed in other arguments, for example, when the first designer and planner or originator or mover is established, their essential needlessness and necessity of existence must be proven on the basis of premises which are also used in the third group of arguments.

Nevertheless, the other arguments have advantages which the third group lacks, that is, the arguments of the third group merely establish that there is an existent which is the Necessary Existent, and other demonstrations are needed to establish that He has knowledge, power, wisdom, and even that He is not a body and is distinct from the material world.

Here, it shall suffice to mention some of the arguments of the third group; and first, to prove the Necessary Existent and then to explain His attributes.

First Demonstration (The Argument from Contingency) One of the famous philosophical demonstrations to establish the Necessary Existent is a demonstration called ‘the demonstration from contingency’ ( burhān-e imkān ) or ‘the demonstration from contingency and necessity,’ and it is formed from four premises: No contingent existent essentially has necessary existence, that is, when the intellect considers its whatness, it sees it as equal in relation to existence and nonexistence, and disregarding the existence of the cause, the necessity for its existence will not be seen.

This premise is self-evident ( badīhī ) and without need of demonstration, for its predicate is obtained through the analysis of the concept of its subject, and the assumption of being contingent is the same as the assumption of lacking necessity of existence. No existent becomes real without the attribution of necessity, that is, until all the ways of nonexistence to it are blocked, it will not come into existence.

As the philosophers say, ‘That which is not made necessary is not brought into existence’ ( al-shay’ mā lam yajib lam yūjad ).