The Rational Demonstrations of Mulla Sadra for the Impossibility of an Infinite Chain of Vertically Aligned Descending Effects and the Necessity of the Physical Body

The existence of the physical body is something that can be proven with the help of sensation. Is it possible to prove the existence of this substance using pure reason, without the help of sensation? Also, there are proofs that demonstrate the impossibility of vertically aligned ascending causes. In other words, the chain of vertically aligned ascending causes must terminate at a being that is not the effect of anything else. However, is it possible for the chain of vertically aligned descending effects to go on ad infinitum? Mulla Sadra was of the opinion that there are purely rational arguments that can prove the existence of the physical body and the termination of the chain of vertically aligned descending effects at this being. In fact, in his magnum opus, the al-Asfar al-Arba’ah, he presented four demonstrations to corroborate this claim. Some of these demonstrations rest upon the necessity of the Hyle and some of them on the generosity of the Necessary Being. Some other demonstrations rest upon the necessity of the existence of beings other than the Intellects. Many of these demonstrations are founded upon the idea that an essentially necessary being is necessary from all points of view. All in all, most of these arguments possess the necessary requirements of demonstration, both from the point of view of their structure and the point of view of their content. Therefore, their conclusions are certain and, logically speaking, acceptable.


Introduction
The Importance of this Discussion The importance of this discussion manifests itself better when we take into consideration the fact that the prime argument of Muslim philosophers for the existence of the physical world relies on sensation. In other words, even though this argument is rational in nature and comes in the form of a syllogism, some of its premises are taken through sensation. For Muslim philosophers of the past, this was not problematic, as they usually considered the knowledge obtained through sensation to be self-evident and certain (Muzaffar 2013: 371-372). Today however, following certain Western thinkers, many Muslim thinkers have called into question the reliability of sensory knowledge. For such individuals, conclusions of arguments for the existence of the physical world that rely on sensation would not be certain, like their premises. However, if pure rational arguments of Mulla Sadra for the existence of the physical world were sound, then such thinkers would still have at their disposal a definite way to prove the existence of the physical world. This is important when we take into account the fact that many Western thinkers, like Berkeley, denied such a world (Misbah Yazdi 1999: 97).

Universal Concepts
In order to clarify the topic at hand, it is necessary to explain certain terms that will be employed throughout this discussion.

An Infinite Chain of Vertically Aligned Descending Effects
An infinite chain of vertically aligned descending effects is in contrast to a few other types of chains of beings. The first is a finite chain of beings, regardless of whether they are vertically aligned or horizontally aligned, regardless of whether they are ascending or descending and regardless of whether they are causes or effects. The second is a chain of beings that are infinite but horizontally aligned with one another, regardless of whether they are causes or effects. When we say that a chain is composed of beings that are horizontally aligned with one another it implies that none of them are the agent and efficient cause for the other; rather, if there is a cause-effect relationship between them, then this is because some of them are preparatory causes for the others. Also, it is not necessary for there to be an ontological hierarchy between these beings and for some of them to be existentially stronger than others; rather, it is possible for them to be equal in the inten-sity of their existence. An example of such a chain of beings is the chain of beings that come into existence in temporal succession and the previous of which are preparatory causes for the later. For example, when water transforms into air, water serves as a preparatory cause for the generation of air. However, water is not a real cause for air and it is not ontologically stronger or weaker than the air it transforms into. If air were to transform back into water the same would be true. If this were to go on ad infinitum, then this would be an example of an infinite chain of beings that are horizontally aligned with one another and which are ontologically equal to one another. Generally, philosophers -in contrast to theologians -say that such an infinite chain of beings is possible; rather, it is necessary. This is because they are of the opinion that causes of the material world, in which this chain would materialize, are eternal, immaterial beings. If the material world were generated in time, then it would imply that an effect would not be present even though its cause existed, which they say is impossible. Therefore, the material world and the successive beings that are generated in it are eternal. However, theologians usually say that the material world and the successive beings that it contains cannot be eternal since the only eternal being, is God (Allamah Hilli 2006: 121). The third type of chain is a chain of beings that are infinite, vertically aligned with one another but are ascending. When we say that a chain of beings are vertically aligned with one another, this implies that there is an ontological hierarchy to these beings and that some of them are existentially stronger than others. When we say that these beings are ascending, then this means that the previous being is not the agent and efficient cause for the later and that each previous being is ontologically weaker that the latter. This is nothing but the chain of beings that the mystics call the Arc of Ascent. For example, in the human being, there is a hierarchy to the different levels of its being. The body is ontologically weaker than the faculties of particular knowledge and these faculties are weaker than the intellect. However, in this chain of successive beings, the previous being is not the agent for the next; rather, at most, it is the preparatory cause for its genesis. Philosophers say that such a chain of beings cannot go on forever. This is because it would mean that there would be no ultimate final cause of the Universe. However, since the final cause is a dimension of the efficient cause, this would entail that there would be no ultimate efficient cause for the Universe, which is impossible. It is also possible for such a type of infinite chain of beings to refer to an infinite chain of efficient causes that never terminates at a being that is not an effect of an efficient cause. This is also something that philosophers consider impossible. The proofs for the impossibility of such a chain are what are discussed in the impossibility of a casual regress. This means that we cannot say that a single effect is S. H. Agha, The Rational Demonstrations of Mulla Sadra for the Impossibility of an Infinite Chain of Vertically Aligned Descending Effects and the Necessity of the Physical Body preceded by an infinite chain of efficient causes which does not terminate at a being that is not the effect of an efficient cause. In this paper we want to examine Mulla Sadra's arguments for the impossibility of a chain of effects that are infinite, vertically aligned with one another and descending. This is a chain of beings the units of which are infinite, form an ontological hierarchy and in which each previous being is the efficient cause for the latter. It means that we want to examine whether it is impossible for a chain of effects to stem from the Ultimate Cause of the Universe, i.e. the Necessary Being, each of which is the agent and efficient cause for the next (and which therefore is ontologically stronger than the being that follows it) and for this chain of effects to never terminate at an effect which is not the agent and real cause for any other being.

The Definition of the Physical Body
To the senses, physical bodies possess dimensions in the three dimensions of space. However, there are different opinions regarding the true nature of the physical body. Some are of the opinion that the physical body is actually composed of parts while some are of the opinion that it is only potentially composed of parts. Those who say that it is actually composed of parts are divided into two groups. Some say that these parts are absolutely indivisible. This is while others say that they possess dimension and are potentially divisible, either in the mind or the external world as well. Those who say that they are absolutely indivisible are divided into two subgroups. Some say that the number of these parts is infinite while others say that it is finite. Those who say that the physical body is only potentially divisible are in turn divided into two subgroups. Some say that it is infinitely capable of division while others say that it is only divisible up to a certain point. Those who say that the physical body is capable of division infinitely are divided into two subgroups. This is because some say that it is composed of matter and form while others say that it does not possess matter; rather, it is sheer form. In this paper, when we refer to the physical body, we are referring to the physical body as it is interpreted by the last group, a substance that appears to possess dimension in the three directions of space and which is only potentially but infinitely divisible and which is composed of matter and form (Tabatabai 2010: 90-91).

Pure Rational Demonstration
By "pure rational demonstration" we mean rational demonstration that none of the premises of which are taken from sensation. Thus, in this paper, we want to examine if it is possible to prove the claim we are attempting to prove without the help of sensation, even as one of the premises of our arguments.

Mulla Sadra's Rational Arguments for the Impossibility of an Infinite Chain of Vertically Aligned Descending Effects and the Necessity of the Physical Body
The 1  In order for the aforementioned argument to be sound, it is necessary to prove the necessary connection between the antecedent and the consequent of its 1 st premise. This can be done in a series of stages which we will explain hereunder.

st Stage of the Argument:
Minor premise: If a chain of vertically aligned descending effects were infinite, then the descending chain of existence would not terminate at a limit.
The truth of this premise rests upon two fundamental tenets of the Transcendent Wisdom. The first is the idea that causation is a property of existence. In other words, a cause is an existent and its effect is also an existent. Of course, this in turn rests upon the principality of existence (Mulla Sadra Shirazi 2006: 181). The second is the idea that every effect is ontologically lower than its cause (Razi 2008: II/635). Therefore, if there were a chain of vertically aligned effects that began from a cause that were not an effect and went on forever, then there would be a chain of existence that began from a 36 S. H. Agha, The Rational Demonstrations of Mulla Sadra for the Impossibility of an Infinite Chain of Vertically Aligned Descending Effects and the Necessity of the Physical Body certain point and descended for eternity, never terminating at a limit and an effect that was not an efficient cause of anything.
Major premise: However, if the descending chain of existence did not terminate at a limit, then the lowest of beings would not come into existence.
Conclusion: If a chain of vertically aligned descending effects were infinite, then the lowest of beings would not come into existence.
2 nd Stage of the Argument: Minor premise: If a chain of vertically aligned descending effects were infinite, then the lowest of beings would not come into existence.
Major premise: However, if the lowest of beings did not come into existence, then a being would not come into existence that was absent from itself and from which everything else is absent.
It is possible to explain this premise in the following manner: The being that is completely present for itself and for which everything else is present is the Necessary Being. The Necessary Being is the ontologically highest being. Thus, the being that is completely present for itself and for which everything else is present is the ontologically highest being. The lower we descend in the grades of existence the more we see this quality diminish. In other words, beings become less present for themselves and other things become less present for them. In other words, existence is presence. The stronger this presence is, the stronger the existence. Conversely, the weaker it is, the weaker the existence. The natural conclusion of this explanation is that the lowest of beings is that being which is the weakest in terms of presence (Mulla Sadra Shirazi 2011: V/5). In other words, it should be absent from itself and everything else should be absent from it.
Conclusion: If a chain of vertically aligned descending effects were infinite, then a being would not come into existence that was absent from itself and from which everything else is absent.

rd Stage of the Argument:
Minor premise: If a chain of vertically aligned descending effects were infinite, then a being would not come into existence that was absent from itself and from which everything else were absent.
Major premise: However, if a being did not come into existence that were absent from itself and from which everything else were absent, then a being would not come into existence.
This premise can be explained in the following manner: Existence is presence and non-existence is absence. Thus, if there were a being whose very existence was its absence from itself and the absence of everything else from it, then its dimension of existence would contain its dimension of non-existence.
Conclusion: If a chain of vertically aligned descending effects were infinite, then a being would not come into existence whose dimension of existence contained its dimension of non-existence.
4 th Stage of the Argument: Minor premise: If a chain of vertically aligned descending effects were infinite, then a being would not come into existence whose dimension of existence contained its dimension of non-existence.
Major premise: However, if a being did not come into existence whose dimension of existence that contained its dimension of non-existence, then the physical body would not come into existence.
This premise can be explained in the following manner: the physical body is a body that essentially possesses dimension. Dimension is capable of being divided into parts that are absent from one another in space. So, parts of a physical body are absent from one another in space. If parts of a physical body are absent from one another in space, then the totality of the physical body is absent from its parts in space. This is because the totality of the physical body contains its parts. However, if the totality of the physical body is absent from its parts in space, then the totality of the physical body would be absent from itself in space. This is because the totality of the physical body contains its parts. Hence, the physical body is absent from itself. Since it is absent from itself, it is absent from other things and other things are absent from it. This is because there is nothing closer to something than itself. If something were absent from itself, then it would be impossible for other things to be present for it. Consequently, the physical body is absent from itself and other things are absent from it (as it is absent from them). So, the nature of the existence of the physical body contains the quality of absence. However, absence is synonymous with non-existence. This is because existence is presence. Hence, the nature of the existence of the physical body contains its non-existence. Thus, if a being did not come into existence that's dimension of existence that contained its dimension of non-existence, then the physical body would not come into existence.
Conclusion: If a chain of vertically aligned descending effects were infinite, then the physical body would not come into existence.

th Stage of the Argument:
Minor premise: If a chain of vertically aligned descending effects were infinite, then the physical body would not come into existence. Major premise: However, if the physical body did not come into existence, then Hyle would not come into existence.
It is possible to explain this premise in the following manner: Hyle cannot exist without the physical form, as it has been proven in its own place (Sabziwari 2011: IV/218). However, if Hyle existed with the physical form, then the physical body would exist, as the physical body is composed of these two beings. So, if Hyle existed then the physical body would surely exist. The converse by contradiction of this principle is that if the physical body did not exist, then Hyle could not exist.
Conclusion: If a chain of vertically aligned descending effects were infinite, then the Hyle would not come into existence.

th Stage of the Argument
Now that the necessary connection between the antecedent and the consequent of the 1 st premise of the argument has been proven it becomes necessary to prove the validity of its 2 nd premise, i.e. the negation of the consequent of the 1 st premise (i.e. the idea that Hyle does indeed exist). This is something that we will now do.
1 st premise: If a chain of vertically aligned descending effects were infinite, then Hyle would not come into existence.
2 nd premise: However, Hyle does exist. The truth of this premise rests upon the proofs for the existence of Hyle, one of which Mulla Sadra points to in the text, i.e. the Demonstration of the Impossibility of the Combination of Actualities. To explain, every physical body has the potential to become something other than what it actually is and the actuality of what it is. This potentiality is an accident. Every accident needs a subject in which it might inhere. Thus, this potentiality needs a subject in which it might exist. However, the subject of this potentiality cannot possess a trace of actuality. Otherwise, it would mean that something actual would have the potential to accept another actuality. However, that which accepts must combine with that which it accepts. In this case, two actualities would combine. However, actuality is tantamount to existence. So, if one actuality accepted another actuality, then one existence would accept and become another existence. This would imply that one being is two beings, which is impossible. Hence, the subject of this potentiality must be sheer potentiality. We call this thing that is pure potentiality, "Hyle". Thus, Hyle must exist. Of course, it is also possible that Mulla Sadra may be referring to the Demonstration by Potentiality and Actuality here. For brevity's sake, we will refrain from explaining this argument in detail.

Conclusion:
It is impossible for a chain of vertically aligned descending effects to be infinite; rather, it must terminate and be finite and, as a result, the physical body must exist.
A Critique of the 1 st Argument Apparently, by presenting the arguments that we are analysing in this paper, Mulla Sadra is attempting to prove the existence of the physical world without taking recourse to sensation. However, it seems that in this argument he has no choice but to use sensation if he wants its conclusion to be certain. This is because one of the premises of this argument is that Hyle exists. However, when we turn to the arguments for the existence of Hyle we see that apparently all of them rely upon sensation to a certain degree. For example, the Demonstration by Potentiality and Actuality relies upon the existence of change -such the existence of movement, to prove the existence of potentiality, matter, form and the physical body (Fayyadhi 2017: II/466-469). However, as Ibn Sina has mentioned in numerous cases, change and movement are things that are understood by the mind with the help of sensation. In addition, the Demonstration by Union and Division proves the existence of the physical body by means of the fact that the physical body can be divided (and its parts separated from one another) and then reunited. However, this is also a phenomenon that can only be understood by the mind with the help of sensation. The same is also true of the Demonstration by the Impossibility of the Combination of Actualities. Thus, even though this argument is a sound argument for the existence of the physical world, it does not seem to serve the purpose for which it was presented. Therefore, since it relies upon the existence of Hyle, it seems to be useless. This is because once Hyle has been proven through sensation, one can easily prove the existence of the bodily form and the physical body through it and there is no need to take recourse to such an elaborate and lengthy argument.

A Summary of the 2 nd Argument
This argument comes in the form of an exceptive syllogism, the 2 nd premise of which is the negation of the consequent of the 1 st premise and can be formulated as follows: 2 nd premise: However, the series of possible beings is not limited to the intellects.
Conclusion: Thus, it is impossible for a chain of vertically descending aligned effects to be infinite (Mulla Sadra Shirazi 2011: V/6).

A Detailed Explanation of the 2 nd Argument
In order for the aforementioned argument to be sound, it is necessary for the necessary connection between the antecedent and the consequent of its 1 st premise to be proven. This can be proven in hereunder.

st Stage of the Argument:
Minor premise: If a chain of vertically aligned descending effects were infinite, then the physical body would not come into existence.
This premise is nothing but the 1 st premise of the 5 th stage of the previous argument, the proof for which was the 1 st -4 th stages of that argument. Therefore, for brevity's sake we will refrain from explaining it here.
Major premise: However, if the physical body did not come into existence, then the series of possible beings would be limited to the Intellects.
This premise is clarified when we take into consideration the fact that every possible being other than the Intellect cannot exist without the physical body. This is because a possible being is either a substance or an accident. If it is a substance, then it is either an Intellect, a soul, a physical body, a form or matter. Accidents are beings that inhere in matter and matter cannot exist without the physical body (what we learned in the previous argument). Thus, accidents cannot exist without the physical body. The soul is a substance that is independent of the physical body in its subsistence but depends upon it in its genesis. Thus, the soul cannot exist without the physical body. Matter is a substance that cannot exist without the physical body, as we learned in the previous argument. Also, form cannot exist without matter, which in turn cannot exist without the physical body. Thus, form also cannot exist without the physical body. So, no possible being other than the Intellect can exist without the existence of the physical body. Hence, if the physical body did not come into existence, then the series of possible beings would be limited to the Intellects.
Conclusion: If a chain of vertically aligned descending effects were infinite, then the series of possible beings would be limited to the Intellects.

nd Stage of the Argument:
Now that the necessary connection between the antecedent and the consequent of the 1 st premise of the argument has been proven it becomes necessary to prove the validity of its 2 nd premise, i.e. the negation of the consequent of the 1 st premise. This is something that we will now do.
1 st premise: If a chain of vertically aligned descending effects were infinite, then the series of possible beings would be limited to the Intellects.
2 nd premise: However, the series of possible beings is not limited to the intellects.
The proof for this premise is the proofs that exist for each of the possible beings that are not Intellects, i.e. accidents, matter, form, the physical body and the soul. For brevity's sake, we will refrain from mentioning these proofs and refer the reader to the related works on this subject.
Conclusion: It is impossible for a chain of vertically aligned descending effects to be infinite.

A Summary of the 3 rd Argument
This argument comes in the form of an exceptive syllogism the 2 nd premise of which is the negation of the consequent of the 1 st premise and can be formulated as follows: 1 st premise: If a chain of vertically aligned descending effects were infinite, then evil would stem from a being that was stingy but necessary.
2 nd premise: However, it is impossible for evil to stem from a being that was stingy but necessary.
Conclusion: It is impossible for a chain of vertically aligned descending effects to be infinite (Mulla Sadra Shirazi 2011: V/6).

A Detailed Explanation of the 3 rd Argument
In order for the aforementioned argument to be sound, it is necessary for the necessary connection between the antecedent and the consequent of its 1 st premise to be proven. This can be proven in a series of stages which we will explain hereunder. Minor premise: If a chain of vertically aligned descending effects were infinite, then the physical body would not come into existence.
This premise is nothing but the 1 st premise of the 5 th stage of the 1 st argument, the proof for which was the 1 st -4 th stages of that argument. Therefore, for brevity's sake we will refrain from explaining it here.
Major premise: If the physical body did not come into existence, then evil would stem from the Necessary Being.
Mulla Sadra explains this premise by stating that even though the physical body is something whose dimension of existence contains its dimension of non-existence (as was mentioned in the 1 st argument), it nevertheless exists. Now, existence is light and non-existence is darkness. This is because light is essentially apparent and it makes other things which are not apparent, apparent. This is also true of existence, which is essentially real and makes other things which are not real, real. Thus, existence is light and non-existence is darkness (Tabtabai 2010: 17-18). So, even though its dimension of light contains its dimension of darkness, the physical body is nevertheless existence and light. Now, light is that which is desirable. And, that which is desirable is good. So, the physical body is good. Hence, if the physical body did not come into existence, then something good would not come into existence. Now, the absence of good is evil. So, if the physical body did not come into existence, then evil would occur in the Universe. However, everything that comes into existence ultimately stems from the Necessary Being. Thus, everything that does not come into existence does not come into existence because the Necessary Being has not created it. So, if evil occurred in the Universe, it would be because the Necessary Being had not created goodness in its place. Hence, if the physical body did not come into existence, then it would be because evil would have stemmed from the Necessary Being.
Conclusion: If a chain of vertically aligned descending effects were infinite, then evil would stem from the Necessary Being.
2 nd Stage of the Argument: Minor premise: If a chain of vertically aligned descending effects were infinite, then evil would stem from the Necessary Being.
Major premise: However, if evil stemmed from the Necessary Being, then evil would stem from a being that was omnipotent and omniscient but necessary. This is because the Necessary Being is omnipotent, omniscient and necessary.
Conclusion: If a chain of vertically aligned descending effects were infinite, then evil would stem from a being that was omnipotent and omniscient but necessary.
3 rd Stage of the Argument: Minor premise: If a chain of vertically aligned descending effects were infinite, then evil would stem from a being that was omnipotent and omniscient but necessary.
Major premise: If evil stemmed from a being that was omnipotent and omniscient but necessary, then evil would stem from a being that was stingy but necessary. This is because if evil stems from a being, then it either stems from it due to the fact that the being does not know how to create good or because it does not have the power to create good or because it is not generous enough to create good. However, the assumption is that the being that we are speaking of is omniscient and omnipotent. So, if it did not create good, then this would have to be because it is stingy and not generous enough to create good.
Conclusion: If a chain of vertically aligned descending effects were infinite, then evil would stem from a being that is stingy but necessary.

th Stage of the Argument:
Now that the necessary connection between the antecedent and the consequent of the 1 st premise of the argument has been proven it becomes necessary to prove the validity of its 2 nd premise, i.e. the negation of the consequent of the 1 st premise. This is something that we will now do.
1 st premise: If a chain of vertically aligned descending effects were infinite, then evil would stem from a being that is stingy but necessary.
2 nd premise: However, it is impossible for evil to stem from a being that is stingy but necessary. This is because a being that is essentially necessary, is necessary from all points of view. Meaning, if the existence of something is necessary, then all of its other aspects and dimensions of perfection should also be necessary. This is a philosophical principle that has been proven in its own place (Mulla Sadra Shirazi 2015: 38). Now, generosity is a type of perfection. Thus, if a being were essentially necessary, then it would have to necessarily possess generosity. So, it is impossible for a being to be stingy but necessary. Hence, it is impossible for evil to stem from a being that is stingy but necessary. Conclusion: It is impossible for a chain of vertically aligned descending effects to be infinite.

An Objection to the 3 rd Argument
It is possible for someone to raise the following objection here: It seems that the premise which stated, "If evil stemmed from a being that is omnipotent and omniscient but necessary, then evil would stem from a being that is stingy but necessary", is questionable. This is because there is no necessary connection between the antecedent and the consequent of this conditional proposition. If evil stems from a being it could be because the being does not know how to create good, does not have the ability to create good, is stingy or because the good that would ensue by the creation of such an evil would outweigh its evil. It seems that the last alternative has not been taken into consideration in this argument. It is possible for the Necessary Being not to create the physical body and to allow this evil to take place not because He did not know how to create it, did not have the ability to create it or was stingy; rather, because the good that would stem from not creating it outweighed its evil.
This objection can be answered in the following manner: in principle, this is true. However, when we examine the situation we find that, in this case, it is impossible for the good that would arise from the non-existence of the physical body to outweigh its evil. This is because in the absence of the existence of the physical body, the human soul would not exist -as the human soul is generated with the physical body. And, if the human soul did not exist, then the Perfect Man would not exist -as the Perfect Man is a type of human being and therefore possesses a soul. Now, the existence of the Perfect Man is greater than all beings put together. So, his non-existence is the greatest of evils. Thus, the good that would arise from the non-existence of the physical body does not outweigh the evil that would arise from it.

A Summary of the 4 th Argument
This argument comes in the form of an exceptive syllogism the 2 nd premise of which is the negation of the consequent of the 1 st premise and can be formulated as follows: points of view, i.e. from the point of view of its termination at the Necessary Being and from the point of view of the non-existence of successive temporal beings.
Major premise: However, this limitation is impossible.
In conclusion: It is impossible for a chain of vertically aligned descending effects to be infinite.

A Detailed Explanation of the 4 th Argument
In order for the aforementioned argument to be sound, it is necessary for the necessary connection between the antecedent and the consequent of its 1 st premise to be proven. This will be explained hereunder.

st Stage of the Argument:
Minor premise: If a chain of vertically aligned descending effects were infinite, then the physical body would not come into existence.
This premise is nothing but the 1 st premise of the 5 th stage of the previous argument, the proof for which was the 1 st -4 th stages of that argument. Therefore, for brevity's sake we will refrain from explaining it here.
Major premise: if the physical body did not come into existence, then the grace of the Necessary Being would be limited from two points of view, i.e. from the point of view of its termination at the Necessary Being and from the point of view of the non-existence of successive temporal beings.
This premise can be explained in the following manner: First of all, if the chain of effects went on forever, the chain of causes would still terminate at the essentially Necessary Being -due to the demonstrations for the impossibility of an infinite chain of causes. Thus, even though from one point of view the number of possible beings would be infinite, from another point of view it would be limited. Also, since the chain of effects does not terminate at the physical body, it would be impossible for successive temporal beings to come into existence. This is because such beings can only come into being by means of temporal generation. And, this temporal generation is preceded by potential, matter and the physical body (Tabatabai 2007: III/760-764), which under the assumption does not exist.
Conclusion: If a chain of vertically aligned descending effects were infinite, then the grace of the Necessary Being would be limited from two points of view, i.e. from the point of view of their termination at the Necessary Being and from the point of view of the non-existence of successive temporal beings.

Sensation as a Testament to the Existence of the Physical Body
The abovementioned arguments were rational demonstrations that did not rely upon sensation. It means that even if someone lacked sensation it would still be possible for him to prove the existence of the physical body and the termination of effects at this being by using these arguments. However, after mentioning these rational arguments, Mulla Sadra points to the fact that these arguments are not necessary for someone to prove this claim; rather, one could also take recourse to sensation to prove the existence of the physical body (Mulla Sadra Shirazi 2011: V/6). Of course, this does not mean that sensation directly witnesses such a being. This is because sensation only has the ability to witness the accidents that surround such a body, such as the planes that surround it and the qualities it bears. Nevertheless, if a specific three-dimensional being did not exist that possessed dimension between these planes and qualities, then a vacuum would occur. Now, such a specific three-dimensional being necessitates the existence of three dimensions in the absolute and unconditional sense of the term. And, such a being should be a substance; otherwise, it would mean that these accidents would not exist in a substance, which is self-contradictory. This substance that possesses dimension in the absolute sense of the term is what we call the "physical body". So, aside from the abovementioned pure rational demonstrations, sensation can also help reason to prove the existence of the physical body.

Conclusion
In this paper, we have examined the purely rational arguments for the existence of the physical body presented by Mulla Sadra. Some of the premis es of some of these arguments were common to all of the arguments while others were common to more than one of the arguments. A few of these arguments were conclusive but relied on sensation. Thus, they did not serve the purpose for which they were intended. Some of these arguments were fallacious in that they led to a vicious circle of argumentation. However, the 2 nd and 3 rd argument seem to be conclusive. Aside from these purely rational arguments, Mulla Sadra was also of the opinion that sensation can also be relied upon to prove the existence of the physical body. In conclusion, it is possible to say that at least two of these arguments can be used to prove the existence of the physical body without the help of sensation.