The existence of God: the influence of Islamic thought on western theology


SHAFAQNA – This article investigates the influence of Islamic thought on Western theology concerning the existence of God. Both Islamic and Western arguments are presented as well as the similarities between the two.

The historical chronology of the arguments is also mentioned, and since the Western arguments were established after the Islamic ones, the influence of the former on the latter is apparent.

As a preliminary to the proof of the existence of God, Ayatollah Misbah Yazdi in his book, “Theological Instructions”, presents a proof for the existence of a Necessary Existence, i.e. an existence that is not the effect of any other existence1. The proof can be summarised as:

  1. All existence is either necessary (wājib al-wujūd) or contingent (mum’kin al-wujūd).
  2. A contingent existence always needs a cause (‘illah).
  3. Every existence cannot be contingent, otherwise each cause would in-turn require another cause, i.e. there would be an infinite recursive series, and no existence would ever come into being.
  4. Therefore an infinite series (tasalsul) of causes is impossible (muhāl) and must terminate in an existence (mawjūd), which is not caused by (ma’lūl) of any other existence, i.e. the Necessary Existence.

Misbah’s argument is a summary of one proposed by Avicenna during the 10th Century. Avicenna (Latin form of Ibn Sina; c. 980–1037) distinguished between essence and existence. He argued that the fact of existence cannot be inferred from or accounted for by the essence of existing things and that existence must, therefore, be due to an agent-cause that necessitates, imparts, gives, or adds existence to an essence. The universe consists of a chain of actual beings, each giving existence to the one below it and responsible for the existence of the rest of the chain below. Because an actual infinite is deemed impossible by Avicenna, this chain as a whole must terminate in a being that is wholly simple and one, whose essence is its very existence and, therefore, is self-sufficient and not in need of something else to give it existence2.

A similar opinion was later adopted by Al-Ghazali (1058–1111), although, he never admits it or uses Avicenna’s language. In Avicenna’s proof, the First Being, which is God, makes all other beings and events necessary. In Al-Ghazali’s proof, God’s will, which is distinct from His essence, necessitates all beings and events in creation3.

Al-Ghazali was an important influence on both Muslim and Christian philosophers. Margaret Smith writes in her book Al-Ghazali: The Mystic (London 1944): “There can be no doubt that al-Ghazali’s works would be among the first to attract the attention of these European scholars… The greatest of these Christian writers who was influenced by al-Ghazali was St. Thomas Aquinas.” 4

St. Thomas Aquinas (1225–1274) was an Italian priest and philosopher who had considerable influence on Western thought. Much of modern philosophy was conceived in development of or opposition to his ideas. One of his most famous works is his five arguments for the existence of God, widely known as the quinque viae (The Five Ways)5:

  1. The Argument from Motion. Thomas argues that since everything that moves is moved by another, and there cannot be an infinite chain of causes of motion, there must be a First Mover not moved by anything else. Note: an Unmoved Mover was an idea first proposed by Aristotle.
  2. The Argument from Efficient Cause. As in the case of motion, nothing can cause itself, and an infinite chain of causation is impossible, so there must be a First Cause.
  3. The Argument to Necessary Being. Our experience includes things certainly existing but apparently unnecessary. Not everything can be unnecessary, for then once there was nothing and there would still be nothing. Therefore, we are compelled to suppose something that exists necessarily, having this necessity only from itself; in fact itself the cause for other things to exist.
  4. The Argument from Gradation. Since all existent things can be compared to such qualities as degrees of goodness, there must be a superlative that is the truest and noblest thing, and so most fully existing. This then, we call God. Note: Thomas does not ascribe actual qualities to God Himself.
  5. The Argument from Design. In all bodies following natural laws, a direction of actions to an end can be observed. Anything without awareness tends to a goal under the guidance of one who is aware, which implies that a Great Designer exists.

Note the similarities of his second and third argument and that proposed by Avicenna and Al-Ghazali.

However, this style of thought is not restricted to medieval philosophy; even contemporary philosophers such as William Lane Craig have used similar arguments. Craig’s basic argument in his book The Kalām Cosmological Argument (1979) states that6:

  1. Whatever begins to exist, has a cause of its existence (i.e. something has caused it to start existing).
  2. The universe began to exist. i.e., the temporal regress of events is finite.
  3. Therefore, the universe has a cause.

He then goes on to propose why an infinite regress is impossible, however this requires an understanding of the philosophy of mathematics and thus outside the scope of this essay.

An objection

Of course, for somebody who is narrow minded, or their heart is closed to accepting the truth, no argument or proof will be of use. Thus for centuries we have seen atheists object to the aforementioned arguments. The most famous of these objections was proposed by David Hume (1711–1776). Hume asks the question, if all existence needs a cause. What caused the existence of God? To this, Ustad Shaheed Motahari answers that the premise of Hume’s question is incorrect; it was not claimed that every existence needs a cause to exist, but rather every incomplete and imperfect existence requires a cause7.


When examining the arguments for the existence of God by western thinkers, the many similarities with Islamic thought is observed. Moreover, since these Western thinkers lived after their Islamic counterparts, the influence of the former on the latter is clear. In addition, the fact that western philosophers, such as William Lane Craig, published essentially the same argument in just the last century testifies to the strength of the original Islamic theology.

Sayed Adnan Hussain

1st year student, Ameerul Mu’mineen Islamic Seminary, Qom.

 Source: The Qom Student Gazette


  1. Misbah Yazdi, M T (2009) Theological Instructions (Āmuzesh-e Aqāyed), Qom: Imam Khomeini Institute For Education and Research
  2. Encyclopædia Britannica Ultimate Reference Suite (2014) Islam: Distinction between essence and existence and the doctrine of creation, Chicago: Encyclopædia Britannica.
  3. Griffel, Frank, “Al-Ghazali”, The Stanford Encyclopedia of Philosophy (Summer 2013 Edition), Edward N. Zalta (ed.), (accessed October 17, 2014).
  4. Wikipedia contributors, “Al-Ghazali,” Wikipedia, The Free Encyclopedia, (accessed October 17, 2014).
  5. Department contributors, ‘Thomas Aquinas, “The Five Ways”’, Department of History and Philosophy, Lander University, (accessed October 17, 2014)
  6. Wikipedia contributors, ‘The Kalām Cosmological Argument’, Wikipedia, The Free Encyclopedia, (accessed 17 October 2014)
  7. Motahari, Morteza (1989) Collected Works of Professor Shaheed Motahari, vol. 1, page 509 (Farsi), Qom: Sadra


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