The proofs or argumentations surrounding God’s existence can be divided into two sets: One set of the proofs consider the creatures as means for argument using the creatures to reach God.  But in the other set of argument, the creatures do not serve as means for proving God’s existence; rather they reach God through the very reality of existence and concept of existence.
The first set of proofs are called inni (which is an inference from effect to cause) and the second set of proofs are called limmi (which is an inference from the cause to cause) or partially inni.[1] , [2] The proof which we now intend to explain i.e. the proof of the veracious is from the second category. The proof of the veracious is an argumentation which benefits from Truth to argue for truth in order to prove the existence of the Truth, the Exalted. Nothing else other than the Truth is used to substantiate God’s existence. Muslim philosophers have provided different explanations and accounts for the proof of the veracious some of which we will mention briefly as under:[3]
Mulla Sadra’s Exposition of the Proof of the Veracious
Sadruddin Shirazi better known as Mulla Sadra is the founder of Transcendental Philosophy. He has given one of the best explanations regarding the proof of the veracious which goes as under:  “If existence, which according to principiality of existence is principal and prime, it is needless of anything. Hence, what we were seeking is achieved and the Necessary Being is proven but if it is essentially needless, in this case it would be an effect and essentially in need of a being which is needless in essence because it is impossible for something which is dependent and needy in nature to take place or come into being without a completely independent and needless being.[4],[5]
We believe your understanding of the proof of the veracious, as per the details provided in your message, is based on the principles of Transcendental Philosophy.  In order to present a correct explanation of the proof of the veracious, we must, first of all, understand and accept some fundamental principles:
1. Principiality of existence versus quiddity being mentally-posited: It is clear that in the concrete external world no being has more than one reality; it is the mind that extracts two concepts (quiddity and existence) from it. For instance, a human being or a tree does not have two external parts to be referred to with the words existence and another with quiddity. It is only through intellectual analysis that we see that quiddity and the particulars of every thing are different from the being and its very existence.
The quiddity of the individual or tree comes to our mind in the way it is in the external world but its existence in the external world is very different from its existence in mind. The effects and impacts which a thing (e.g. fire) has in the external world are with it in the mind. It becomes clear, therefore, that existence or quiddity or in other words, existence and whatness, are two separate issues. Indeed, without existence no quiddity shall exist. It is only existence that helps bring into existence the quiddity of tree or human being from non-existence; otherwise quiddity by itself is nothing and has no external connection with anything. As the famous saying goes, “quiddity, by itself, is neither existent nor non-existent”[6]; it is only itself (quiddity). Quiddity qua quiddity is incapable of making itself enter existence and this signifies the fact that it is not real.
2. Gradation of existence: Mulla Sadra is a staunch proponent of modulation and gradation of existence (tashkik al-wujud). The semantics of the term ‘existence’ and its modulated singularity commits Mulla Sadra to a reality that is equally modulated and singular. Existence is a singular reality, as the phenomenal experience of existence as multiple is illusory. But multiplicity in this world still needs to be explained. Different existents in this world are thus different, intense degrees of a single whole. Thus there is a horizontal and a vertical hierarchy of existence that is connected and involved in a whole chain of existence.
3. Simplicity of existence: Existence is a simple reality which does not have a part and is not a part of something either because we do not have anything other than existence.
4. Effects are but aspects and manifestations of the cause: Cause, causality and effect are interrelated concepts that are not detachable from each other. According to Mulla Sadra, the effect by itself, since it is effect, has no reality other than reliance and dependence and has no meaning other than being effect and subordinate, without having an essence subject to these meanings, as the absolutely originating cause has no essence and reality other than being the principle and source of everything and all relations and dependence go back to him.[7]  
Considering the above principles, the explanations which you have provided in your message is better to be presented in the following way:
The reality of existence is either absolute and simple or finite and limited. If it is absolute, then that is the point and the Necessary Being is proved thereby. In case it is limited and finite – as in the case of things around us which are limited – there must be absolute and infinite existence which the finite existents should depend on for their existence; otherwise it would mean that the effect comes into being without a cause. If it is not absolute and infinite, again it would mean that the finite being depends on something other than itself. And if again we say that this existent is limited, then we would ask about that existent itself and this will go on endlessly and lead to a circle (daur) or endless chain (tasalsul) in the reasoning. Both the vicious circle and endless regression of causes are unacceptable and invalid.
 
Note:
It is necessary to note in connection with this explanation that studying the entities and beings around us help us prove the principiality of existence but they have no role in explaining the proof [burhan] itself. That is because among the concomitants and benefits of the ‘proof of the veracious’ is that they do not use anything other than God for argumentation. If you look carefully at the argument, you will come to know that the argument is based on the reality of existence which is either absolute or infinite. If the reality of existence is absolute, the point we wanted to prove is proved thereby. And if they are limited and finite, it should depend on an absolute entity for their existence. That absolute entity is the Necessary Being or God, the Exalted.

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