1- the cause, i.e. the originator
2- the effect, i.e. the originated
3- causality, i.e. the origination.
These three concepts can only be separated by a mental assumption or metaphor. They are not separable from each other even in the mind and with an intellectual analysis, except in an intellectual metaphor.
Cause, causality and effect are interrelated concepts that are not detachable from each other neither in reality nor in our understanding. Mulla Sadra says:
“The effect by itself is a simple thing like the cause by itself and that is when the attention is limited to them. When we abstract the cause from whatever does not bear on its causation and influence, that is, when the cause is considered as such and when we abstract the effect from whatever does not bear on its causedness it becomes clear and certain that what is called as effect has no reality other than the reality of its originating cause so the intellect cannot refer to the entity of effect disregarding the entity of it originator…
Therefore, the effect by itself has no reality in its causedness except that it is dependent and relational and has no meaning other than being an effect a-subordinate without having an essence exposed to those meanings, just as in the case of the absolute originating cause being principle, source, origin and followed is the same as its essence”.3
Causality in the way explained above implies certain principles and rules, whose denial would be equal to the denial of the principle of causality itself. The first principle implied by the principle of causality is the principle of necessitation of effect or the relation of necessity between the cause and effect. Mulla Sadra says:
“Having proved that no contingent comes into existence without something making its existence outweighing its nothingness and does not become annihilated without something making its nothingness outweighing its existence, so both sides have to be preponderated by an external cause, now we say: that preponderator will not be preponderator unless its preponderance reaches the level of necessity.
Therefore, unlike what most theologians have thought if the preponderance caused by an external cause does not reach the level of necessity it will not be sufficient for the existence of the contingent, because as long as the contingent conveys both possibilities it will not exist. Is this not the case that if its existence is not made necessary by something else its both existence and non-existence would be possible, so no side is determined and to would still need something to preponderate either existence or non-existence.”4
In this way, Mulla Sadra takes the principle of necessitation of effect as a result of the principle of causality itself and its denial to be identical with the denial of causality, because the principle of causality is based on needs of the contingent for a cause that puts an end to the state of equality of both existence and non-existence which is implied by causedness. As long as the cause does not necessitate its effect, it has not removed the state of equality.
Principles such as impossibility of separation of the effect from its cause and necessity of resemblance of cause and its effect in their generic reality are some other important principles derived from the principle of causality.
On the basis of asalat al-wujud, to conclude the above-mentioned principles from the principle of causality is more obvious and more decisive. For example, to draw the necessary relation between cause and effect from the principle of causality on the basis of asalat al-wujud a little reflection is enough to understand the concept of causality and necessity of originating effect by cause.
According to asalat al-wujud necessity is an inevitable implication of ‘being’ and all its levels, states and belongings. The essence of the first cause and whatever is created by it is being and necessity. Dependence on the self-subsistent is the essence of effect and also causation, influence, generosity and graciousness of the first cause is its essence, so the necessity of the existence of the effect is the same as its essence on the one hand, and the same as the essence of the cause on the other hand.
According to this fact, cause necessarily and essentially requires creation of effect and effect also necessarily and essentially requires dependence on cause and creation by cause. Thus, the principle of necessity of creation of effect by cause is a necessary and inevitable result of the principle of causality.
Another important philosophical law, which is derived in the light of causality from asalat al-wujud, is the problem of criterion of need for a cause. This problem is one of the supreme problems discussed in Islamic philosophy and is exclusive to it. Muslim theologians take non-eternity (huduth) as the criterion of need for cause, that is, they believe the reason for having need for a cause is non-being and then coming to be. Since the existence is preceded by non-existence, there must be a cause that led to this transition from nothingness into being.
Muslim philosophers prior to Mulla Sadra developed strong arguments against the theory of theologians and proved that non-eternity cannot be the reason for need, because it is possible to suppose a being which is eternal and at the same time in need of a cause on which it eternally depends. Philosophers before Sadra held that the criterion is contingency.
In other words, the main reason for having need for a cause is the fact that the thing by itself possesses no necessity for existence and non-existence and has equal relation to both existence and non-existence. This logically results in the necessary relation of effect to cause, because as mentioned above as long as the main reason of need for cause is contingency (non-necessity of existence and non-necessity of non-existence), what the cause of existence has to grant the effect is necessity of existence and what the cause nothingness has to grant is the necessity of nothingness.
Mulla Sadra in his excellent studies viewed the theory of his predecessors imperfect and appropriate for the universe of natures. In his studies, he proved that when we consider the relation between nature of something and existence or non-existence the view of previous philosophers is true, because nature of a contingent being has equal relation to both existence and non-existence and none of them is necessary for it.
Therefore, to become existent or non-existent it needs a cause that grants necessity of existence or necessity of non-existence to it.
However, according to asalat al-wujud and subjectivity of nature, what is created by the cause is the existence of effect. Existence has no equal relation to existence and non-existence, so the view of previous philosophers cannot be true. Therefore, the criterion of need of being of effect for cause is not the equal relation of existence and non-existence to the existence of effect or contingency.
The criterion is existential poverty or in other words dependence or relationality of existence. If we reflect on the existence of effect we will find it dependent and subordinate. This dependence and non-self- subsistence have made the effect in need of the cause. Therefore, need for cause is the same as the essence of effect and identified with its existence.
As mentioned earlier, the essential dependence of effect on its cause results in the necessary relation between cause and effect. According to this philosophical analysis, the essence of effect is an inseparable result and outcome of the essence of cause and impossibility of separation of effect from cause is another expression of necessitation of effect by cause.
3. Mulla Sadra, Al-Asfar al-Aqliyyah al-Arbi‘ah, vol. 2, pp.229-30.
4. Mulla Sadra, Al-Asfar al-Aqliyyah al-Arbi‘ah, vol. 1, pp. 221,222.