The Roman Catholic Dominican monk Thomas Aquinas (1225 – 1274) is considered by many to be the greatest theologian in Western religion (Pojman, 2003, 462). Indeed, his great achievement was to produce a vast synthesis of all that had been best argued in Western thought up to his time, and demonstrate it to be compatible with Christian belief. Throughout his various works, Aquinas remains scrupulous about maintaining the distinction between philosophy and religion, or between reason and faith (Magee, 2001, 59). “For example, he says that as far as rational thought is concerned the questions whether the world had a beginning and will have an end are undecidable: in either case the truth could lie either way. But he says, as a Christian he believes (though it is not rationally demonstrable) that the world had a beginning, having been created by God, and will one day have an end.” (Magee, 2001, 59). Saint Thomas’ works include numerous translations and commentaries on Aristotle, as well as theological writings. Moreover, the two major texts for which Aquinas is best known are the Summa contra Gentiles (‘Against the errors of the Infidels’), a text-book for missionaries and the Summa Theologiae, which is universally acknowledged to be the crowning achievement of medieval systematic theology (Blackburn, 1994, 22).
In this essay, I first give a brief explanation of the five proofs of God’s existence made by St Thomas Aquinas, deriving from his well-known work, as mentioned previously, the Summa Theologiae. Then, I discuss the relevance of these five proofs of God’s existence in the Modern times. Finally, I conclude.
Five proofs of God’s existence
The first and most basic method given by Aquinas is the proof that proceeds from the point of view of motion. Things on earth undergo change is certain and in accord with experience. Now, everything that is moved is moved by something; nothing, indeed, is changed, except it is changed to something that it is in potentiality. Moreover, anything moves in accordance with something actually existing; change itself, is nothing else than bringing forth something from potentiality into actuality.
The second proof of God’s existence follows closely to the first and arises from the principle of causality. “Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate, cause.” (Pojman, 2003, 466). Aquinas explains that in the world of sense there is an order of causes and effects. He taught that it is impossible for anything in the world to be the efficient cause of itself. St Thomas gives the example of the existence of a clock. Indeed, nothing can cause itself into existence, not even a clock. A clock cannot will itself into existence; it must be created and caused into existence by something else. The something else, which creates the existence of a clock, is a clockmaker, and yet, the material of the clock and the clockmaker did not cause themselves to exist. In other words, something else must have caused their existence. All things can attribute their existence to a first cause that began all causes and all things. We call this first cause God. Aquinas thus evokes a being which has to be the first efficient cause, and for Aquinas this being must be God (Pojman, 2003, 466).
Next, St Thomas third proof describes that anything that comes into existence must come to an end. He explains the transitory nature of this universe where things are generated and then corrupt over time. According to Aquinas, it is impossible that things exist eternally since it is impossible for these things always to exist indicating a time when they did not exist. Moreover, at some time there would be nothing in existence, and from that, nothing could begin to exist. “But every necessary thing either has its necessity caused by another, or not.” (Pojman, 2003, 466). If then nothing existed, it would be impossible for anything to begin, and there would now be nothing existing, which is admittedly false. Hence not all things are mere accidents, but there must be one necessarily existing being. Necessary things have a cause for their necessary existence; nevertheless, the chain of causes cannot go back infinitely. Thus, as was already explained in his second proof, there must have been a first cause that was not of transitory nature that could have generated the beginning of nature, which all call God.
Aquinas thus concluded that there must be a being that has its own necessity, which does not need to receive it from another, and thus becomes the actual cause of all necessity. For Aquinas, such a being can only be God. (Pojman, 2003, 466).
The fourth proof of God’s existence deduced by Aquinas is the presence of a certain gradation in things for there is found a greater and a less degree of goodness, truth, nobility, and so forth. Things in this world are thus compared through degrees of perfection. As a consequence of these judgments, there must be, for example, something, which is the truest, something best, and most noble, consequently, something that is the greatest being (Pojman, 2003, 466).
Finally, the last proof given by St Thomas Augustine is “Therefore some intelligent being exists by whom all natural things are directed to their end.”(Pojman, 2003, 467). Aquinas viewed that every living entity must die, not accidentally, but according to a plan. Natural bodies, for example, are operated in accordance with a plan. The laws governing the universe presuppose a universal legislature who authored the order of the universe. It appears from this that they are operated always or the more frequently in this same way the closer they follow what is the Highest. Whence it is clear that they do not arrive at the result by chance but because of a purpose. The example is given of a cup. If you drop a cup on the floor, it shatters into bits and has become disordered, but if you were to drop bits of the cup, they would not assemble together transforming into a cup. This is an example of the inherent disorder prevalent in the universe when things are left to chance. Hence it becomes clear that things do not arrive at the result by chance but due to a purpose. “Inorganic objects are without knowledge: they cannot, then, tend towards and end unless they are directed by someone who is intelligent and possessed of knowledge, as ‘the arrow is directed by the archer’.” (Copleston, 2003, 344). Thus, according to Aquinas, the existence of order and natural laws presupposes a divine intelligence that authored the universe into being, namely God.
Relevance in Modern Times
Some objections to Aquinas’s first three proofs of God’s existence can be observed, and Copleston (2003, 341) indicates these in detail. First he describes that when Aquinas mentions the ‘infinite series’ to be impossible, Aquinas does not think of a ‘horizontal’ series stretching back in time.
St. Thomas did not believe that it can be proved philosophically that the world was not created from eternity: he admits the abstract possibility of the world’s creation from eternity and this cannot be admitted without the possibility of a beginningless series being admitted at the same time. (Copleston, 2003, 341).
As Copleston (2003, 342) describes here, when Aquinas talks about the ‘infinite series’ in his proofs, he is actually referring to the infinite series in the ontological order of dependence. “In other words, he denies that the movement and contingency of the experienced world can be without any ultimate and adequate ontological explanation.” (Copleston, 2003, 342). Thus, the emphasis made by Copleston lies on the conclusions of Aquinas, namely that the ‘unmoved mover’, the first ’cause of all causes’, and the final ‘necessary being’ are God. Nevertheless, Aquinas has not proved that this being must be considered to be God by others as well.
Obviously, if anything exists at all, there must be a necessary Being: thought must arrive at this conclusion, unless metaphysics is rejected altogether; but it is so obvious that the necessary being must be the personal Being whom we call God. That a purely philosophical argument does not bring us to the full revealed notion of God needs no elaboration; but, even apart from the full notion of God as revealed by Christ and preached by the Church, does a purely philosophical argument give us a personal Being at all? (Copleston, 2003, 342).
Copleston (2003, 342) observed Aquinas’s proofs from a different perspective. This perspective points out that Aquinas, being a faithful Christian, believed in God and was therefore rushed in identifying the ultimate being with the God of Christianity. “Did St. Thomas’s belief in God lead him perhaps to find more in the conclusion of the argument than was actually there?” (Copleston, 2003, 342). Since Aquinas was firstly a theologian, it was natural for him to think of God as the ultimate end of all conclusions. As one may construe, those who believe in Him more easily recognize God. Indeed, a certain amount of faith in God is required to accept Him as the first cause and necessary being, as confirmed by Copleston; “The phrases in the question should, therefore, be understood as expression of the fact that God is recognised by all who believe in Him to be the first Cause and necessary Being, not as an unjustifiable suppression of further argument.” (2003, 343).
Nonetheless, the proofs given by Saint Thomas are not meant to defeat the “professed atheist” of the modern times, he had not written this treatise with that in mind. For instance, if he had to deal with the Marxists, he would have dealt with the proofs differently (Copleston, 2003, 343). Nevertheless, Aquinas did aspire to prove the existence of God. He believed that this natural knowledge of God is confused and vague, and thus necessitates clear explanations to be made explicit (Copleston, 2003, 336). In the modern world, however, such elucidation is even more essential in order to prove the existence of God since faith in God is not a common value. Saint Thomas, however, did not live in a world where theoretic atheism was a common belief (Copleston, 2003, 336).
To us indeed, living in a world where atheism is common, where powerful and influential philosophies eliminate or explain away the notion of God, where multitudes of men and women are educated without any belief in God, it seems only natural to think that God’s existence requires proof. (Copleston, 2003, 336).
Thus Copleston’s explanation, in my opinion, is extremely accurate. If St. Thomas lived in our modern world where God’s existence is obliged to be proved in detail, Aquinas would probably treat his proofs in a more elaborate and developed manner. Copleston states that Saint Thomas was not dealing primarily with atheists even in his Summa contra Gentiles (a theological text-book), but rather with Mohammedans, who had a firm belief in God (Copleston, 2003, 343). These circumstances should be taken into consideration.
The way in which St. Thomas justifies the proofs may perhaps cause some dissatisfaction in the reader; but it must be remembered that the Saint was primarily a theologian and that, as already mentioned, he was concerned not so much to give an exhaustive treatment of the proofs.” (Copleston, 2003, 345).
One can understand that if Aquinas did live in the modern world where atheism is common, he would not only focus his attention on people who have faith in God, but also those who do not entirely believe in God, or consider God the ultimate goal of life. Subsequently, this work can be put into the hands of his modern followers who can develop his proofs in further detail according to the modern society.
In conclusion, in this essay, I briefly explained Saint Thomas Aquinas’ five proofs of God’s existence. Then I discussed how one could perceive his proofs in the modern age and whether his arguments are still relevant in modern society. Indeed, his proofs were not directed to a conversion of atheists, and therefore, need to be developed in greater detail and depth. His arguments seem to provide a good basis for one to develop further into a suitable argumentation for the modern times. Saint Thomas was a theologian, a Christian, and thus had firm belief in God. His faith in God most probably facilitated the development of his arguments and prevented him from entering into great detail. Moreover, at Aquinas’ time, many were believers in God, unlike the modern times. Nevertheless, a modern disciple of Aquinas could consider recent theories, give an explanation of Aquinas’s five proofs in a more appreciable way, and simultaneously defend Aquinas’s arguments (Copleston, 2003, 343).
Although Saint Thomas’ arguments may be convincing to some, they may not to others. In my opinion, it lies mainly on the individual self to make such a decision. If one analyzes such arguments with a mindset such as “God does not exist”, naturally, one will find numerous objections and inconsistencies on all levels. However, if one does have some faith in God, naturally these proofs of God’s existence will be accepted without numerous oppositions. In the end, it lies on the individual whether they desire to remain confused about God’s existence as well as finding their own