The reasoning of possibility and necessity
- Updated On Friday, 15 August 2014
- Written by Ayatullah Misbah Yazdi
- Editor Kawther Rahmani
- Supervisor Sayyed Roohullah Musavi
- Published on Saturday, 31 July 2010
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- Hits: How do you prove that God exists using the reasoning of possibility and necessity?
All propositions - regardless of them being simple or complex - have two fundamental concepts (subject and predicate). For example, in the following axiom, 'the sun shines,' which establishes shining for the sun, 'sun' is the subject and 'shining' is the predicate. The establishment of a predicate for the subject has no more than three states: it is either impossible, such as 'the number three is greater than the number four,' or it is necessary, such as, 'the number two is half of four' or it is neither impossible nor necessary, for instance, 'the sun is above our head.' In logical terminology the first proposition has the state of impossibility (imtina'), the second proposition is given the attribute of necessity (wujub), and the third state is considered as possibility (imkan). However, in philosophy, only existence is discussed and those things which are being incapable of being or of occurring and impossible (mumtani') will never have an existence (al-wujud al-khariji). For this reason philosophy regards existence from an intellectual perception as being either necessary or possible. Necessary existence is known as an existent which exists in-itself and does not depend upon another existent. Naturally such an existent will have no beginning and no end, because the non-existence of something in a particular time is an indication that its existence is not from itself. In order for it to come into existence it needs another existent, which is the cause or the condition for its realisation. The absence of this condition or cause would be the reason for annihilation. Possible existence (mumkin al-wujud) is known as an existent which does not exist in-itself and depends upon another existent in order for it to be realised. This division, which has taken place through intellectual perception, essentially disregards the existence of the impossible (mumtani' al-wujud), but it does not have any indication whether the existent is either a possible existent or necessary existent. In other words, the genuineness of this perception can be conceptualised in three essential forms: 1. Every existent is a necessary existent. 2. Every existent is a possible existent. 3. Some existents are necessary existents and some are possible existents. On the basis of the first and third assumptions, the existence of a necessary existent is established, therefore the assumption that should be reviewed is whether all existents are possible existents or not. However, by disproving this assumption (that all existents are possible existents), the existence of the necessary existent is definitely and confidently proven. The establishment of unity and other attributes must be proven with other arguments. Therefore, in order to disprove the second assumption, additional arguments must be utilised, one of which is that it is impossible for all of the existents to be possible existents. As this argument is not self-evident, it will be explained as follows: every possible existent needs a cause and it is impossible to have an endless chain of causes. Thus the endless chain of causes is compelled to terminate at an existent which is not in need of a cause, i.e., the necessary existent. This argument has introduced other philosophical concepts which require a brief explanation of it and things related to it. A. Cause and effect If an existent requires another existent and depends upon that other existent for its being, then in philosophical terminology the caused existent is known as the effect and the other existent is known as the cause. However, it is possible that a cause can also be an effect and be a dependable existent not absolutely free from need. If a cause is absolutely free from need and does not depend upon any other existent then it will be the Absolute cause. By now we have become familiar with the definition of the terms cause and effect. We will now provide an explanation of the premise mentioned (every possible existent needs a cause). Possible existence does not exist in-itself and has no alternative other than to depend upon another existent. Thus every predicate which is recognised for the subject is established either by itself (bil-thaat) or by means of other than itself (bil-ghayr). For example, every thing either shines in and of itself or requires something else for its illumination, or every body is oily in itself or needs oil in order to become oily. It is impossible for something in itself to not be illuminating or oily and not receive light or oil from something else, and at the same time be oily and illuminating! Hence, the establishment of existence for a subject is either through its essence or by means of other than itself, and when it is not through its essence then it has to be by means of other than itself. Therefore, every possible existent, which is not realized through its essence, is bound to be realised by means of other than itself, which implies that it is an effect. This provides us with the fundamental principle of the intellect, that every possible existent needs a cause. However, some have conceived that the principle of causation means that all existents need a cause and therefore God needs a primary cause. They have overlooked the fact that the subject of the principle of causation is existence in the possible sense and its effect and not in the absolute sense. Not all existents require a cause; only those which are dependent and in need require a cause. B. The impossibility of an endless chain of causes The last premise used for this argument is that the chain of causes should terminate at an existent, which is not an effect. In technical terms an endless chain of causes is impossible. It is thus established that the necessary existent is the initial cause, which is self-subsistent and depending on no other existent. Philosophy has come up with many arguments in order to disprove infinite series (tasalsul); nevertheless, with the minimum of reflection infinite series would almost seem to be self-evident. That is to say, considering the existence of an effect requires a cause and is conditional upon that cause. Furthermore, if this state of being caused (ma'luliyyah) and this conditionality are universal, then no existents would be realized anywhere. This is because the assumption of a few existents that are dependent without the existence of an existent is against the intellect. Let us assume that a group of runners are waiting to begin a race. They have all decided that they will not commence running until the others have. If this decision prevails among all of them, then none of them would begin to run. In the same manner if the existence of every existent is conditional upon the realisation of another existent, never would an existent come into being. The realisation of an external existent indicates that there is an existent which is needless and unconditional. C. Affirmation of the argument At this moment, with the understanding of the premises mentioned, we would like to re-affirm our argument. Every thing that can be considered as an existent has no more than two states: 1. The existent for which existence is necessary and exists by means of its own essence. In technical terms, this is known as the necessary existent. 2. The existent for which existence is not necessary and depends upon another existent in order to be realised. In technical terms, this is termed as the possible existent. It is self-evident that if the realisation of a thing is impossible, then it will never come into being; hence, every existent is either a possible existent or a necessary existent. By focusing upon the concept of possible existence it becomes clear that the every referent of this concept is an effect and requires a cause. Furthermore if an existent does not exist by means of its essence then it becomes necessary that it came into existence through another existent because every attribute that is not existent by means of its own essence has to exist by means of other than itself. The principle of causation affirms that every existent that is dependent and possible requires a cause. But not every existent requires a cause; otherwise one would conclude that there must then be a cause for God. From another angle, it must be seen that if all existents were possible existents, then an existent would never be realised. This is like assuming that a group of people had conditioned their actions upon each other, which implies no activity. However, the external activity of existents establishes the existence of the necessary existent.