Program / Course 14: Arguments for the Existence of God / Lesson 4.1
What you will learn
- Explain what the word kalam means and where the tradition began.
- Describe the arguments of John Philoponus, al-Ghazali and Bonaventure against an infinite past.
- Explain why Aquinas disagreed that reason can prove a beginning.
- Trace how the medieval argument differs from the modern one.
The big idea
The kalam argument is a family of arguments that the world must have had a beginning and therefore a cause. Kalam is an Arabic word for speech or discussion, used for the tradition of rational theology in Islam. The argument was developed by the Christian John Philoponus in sixth-century Alexandria, was taken up by Muslim and Jewish thinkers, including al-Ghazali, and was defended by the Franciscan Bonaventure. Thomas Aquinas disagreed that reason can prove the beginning, so Christians have been divided from the start.
Key terms
- Kalam
- An Arabic word meaning speech or discourse. It names the tradition of rational argument about God in medieval Islam.
- Eternity of the world
- The view, held by Aristotle and some of his followers, that the universe has always existed.
- Actual infinite
- A completed collection with infinitely many members.
- Incoherence of the Philosophers
- A work of al-Ghazali (about 1095) attacking claims of the Aristotelian philosophers, including that the world is eternal.
- Creation out of nothing
- The doctrine that God made everything that is not God, from no pre-existing material. In Latin, creatio ex nihilo.
- Traversing the infinite
- Going through an infinite series one member at a time. Medieval thinkers held this impossible.
- Article of faith
- A teaching accepted on the basis of revelation, not proved by reason.
Background
Aristotle taught that the universe has no beginning, and many of his later followers, Christian, Muslim and Jewish, were troubled by this, since their scriptures speak of creation. John Philoponus (about 490 to 570), a Christian philosopher at Alexandria, wrote works arguing that Aristotle was mistaken and that an infinite past is impossible. His arguments were translated into Arabic and influenced later thinkers.
In the Islamic world the mutakallimun, the practitioners of kalam, developed such arguments further. Al-Kindi (ninth century) argued that an actual infinite cannot exist. Al-Ghazali (1058 to 1111) in his Incoherence of the Philosophers criticized the view that the world is eternal. The Jewish thinker Saadia Gaon (882 to 942) used similar reasoning. Their arguments reached the Latin West in the thirteenth century.
The modern form of the argument associated with William Lane Craig, who gave it the name kalam in his 1979 book The Kalam Cosmological Argument, draws on this tradition. The next lesson studies it.
Step-by-step explanation
Step 1: The problem the tradition faced
If the universe has no beginning, it seems to need no creator in the sense of one who brings it into being. The kalam thinkers wanted to show that an eternal universe is impossible, so that creation in time is rational. They did not see themselves as arguing from the Bible or Quran but from reason.
Step 2: Philoponus
Philoponus argued that if the past were infinite, an infinite number of days would have passed to reach today, which seems impossible, since an infinite series cannot be completed by successive addition. He also argued that each day adds to the total, so an infinite past would have an infinite number increased by more. Philoponus was a Christian and wrote that the argument supports the doctrine of creation.
Step 3: Al-Ghazali
Al-Ghazali argued that the world, which has a beginning, needs a cause that brings it from non-existence into existence at one time and not another. He used a number of arguments against an infinite past, including a version of the claim that infinite sets lead to absurdity. He also argued that a God who freely wills the world explains why it began when it did. He was concerned to show that the philosophers’ denial of creation was not proven.
Step 4: Bonaventure
Bonaventure (about 1217 to 1274) was a Franciscan teacher at Paris. He argued that the world must have had a beginning because an infinite number of past days cannot have been traversed. He thought it contrary to reason, as well as to faith, to hold that the world is eternal. Thomas Aquinas, his Dominican contemporary, thought the arguments failed.
Step 5: Aquinas’s disagreement
Aquinas held that the beginning of the world is an article of faith, known by revelation and not demonstrable by reason. He thought that Bonaventure’s arguments were not conclusive and that an eternal world created by God, if there were one, would not contradict reason. He insisted, however, that the world does in fact have a beginning, as the Church teaches. This is a model of two Christians sharing a faith and disagreeing about what reason can prove.
- Why would a believer in creation want to rule out an eternal universe?
- Is an infinite past more puzzling than a finite one?
- What difference does it make that Philoponus was a Christian and al-Ghazali a Muslim?
- What does Aquinas’s disagreement show about how reason and faith relate?
- Is it possible to grasp what it means to traverse an infinite series?
- Why might it matter that the argument has roots in three religions?
Examples
Counting down from infinity
Someone claims to have been counting down from infinity and to have just reached zero. Defenders of the argument say this is absurd, since there is no point from which to start. They say an infinite past is similar: an endless series of days cannot have been completed. Critics reply that the cases differ, since a past with no beginning has no first day to start from.
Aquinas and Bonaventure
Two friars, one Dominican and one Franciscan, taught in Paris in the 1250s and 1260s. They agreed that God created the world and disagreed on whether reason can show that it began. Their disagreement was friendly and philosophical, not a quarrel over doctrine.
A tradition crossing borders
The Arabic translations of Philoponus carried his arguments to Baghdad, where they shaped Muslim theology, and the writings of Muslim and Jewish thinkers were then translated into Latin. A single argument passed through three religions and several languages.
Different perspectives
Catholic
The Fourth Lateran Council (1215) taught that God made both spiritual and bodily creatures from the beginning of time. Catholic thinkers have since divided on whether reason can show it: the Franciscan tradition with Bonaventure says yes, while Thomists with Aquinas say it is known only by faith.
Orthodox
Orthodox theology teaches creation out of nothing and a created time, and its theologians, including Basil and Gregory of Nyssa, argued against the eternity of matter. Philoponus belonged to the Greek Christian world, though he was condemned for his views on the Trinity at a later time and is not an Orthodox authority.
Protestant
Protestants hold creation in time as a teaching of Scripture. Evangelical philosophers, notably Craig, have revived the kalam argument. Some other Protestants, such as many Reformed theologians, are less interested in such arguments.
Islamic and Jewish views
Within Islam, the kalam tradition defended creation against Aristotelian philosophers such as Avicenna, who held that the world is eternal though dependent on God. In Judaism, Saadia defended a beginning and Maimonides held that reason could not settle it, siding on this point with Aquinas, who followed him.
Skeptical views
Skeptics note that the medieval arguments rested on ancient views of infinity that mathematics has since revised. They add that cosmology, not philosophy, is the proper means to ask whether the universe began.
Why it matters
The kalam argument is often presented as a new idea. Knowing its history shows that it is old, that it crossed religious lines, and that great Christian thinkers disagreed on its strength. This guards against both overconfidence and dismissal.
Common misunderstandings
Misunderstanding: The kalam argument is a recent invention by American apologists.
Correction: It goes back to the sixth century and has roots in Christian, Muslim and Jewish thought. Its current form was developed in the 1970s.
Misunderstanding: All Christian thinkers accepted that reason proves a beginning.
Correction: Aquinas, the most influential medieval theologian, denied it, while accepting the beginning on faith.
Misunderstanding: Kalam means the argument from a first cause.
Correction: The word names a tradition of Islamic rational theology. The argument is one of its products.
Misunderstanding: Al-Ghazali, a Muslim, has nothing to do with Christian thought.
Correction: His work was widely read, and the argument as a whole reached Latin Christians through Arabic sources.
Knowledge check
What does kalam mean and where does the tradition come from?
Kalam is an Arabic word for speech or discourse. It names the tradition of rational theology in medieval Islam, which developed arguments for a beginning of the world. But the main ideas have earlier roots in the Christian philosopher Philoponus, and similar arguments were used by Jewish thinkers like Saadia Gaon.
What was Philoponus’s main argument?
He argued that an infinite past would require that an infinite number of days had been passed through to reach the present, which seemed impossible since an infinite series cannot be completed by successive addition. He used this to defend creation against Aristotle’s teaching that the world is eternal.
Why did Aquinas disagree with Bonaventure?
Aquinas held that the beginning of the world is known by faith and cannot be shown by reason. He thought the arguments against an infinite past were not conclusive and that an eternal created world would not be contradictory. Both men accepted that the world began, but they differed on what reason can demonstrate.
Why do modern critics say the medieval arguments are dated?
They say the arguments used older ideas of infinity, and that modern mathematics, following Cantor, treats actual infinities as consistent. They also say cosmology, not abstract reasoning, is the proper way to ask whether the universe had a beginning. Defenders reply that the philosophical points still stand.
Think it through
- Does it matter to faith whether reason can prove the world began?
- What does the cooperation of Christian, Muslim and Jewish thinkers suggest?
- Do you think Aquinas or Bonaventure had the better position?
- How should a believer treat an argument that great teachers have disagreed about?
Independent assignment
Two friars compared
In your own notebook, write 300 to 450 words. Summarize in one paragraph each the positions of Bonaventure and Aquinas on whether reason can show that the world began. Then write a paragraph on what each would say to a skeptic who holds that the universe is eternal. Finish with your own view of which position is stronger. Do not send this to anyone.
Further study
- Stanford Encyclopedia of Philosophy, Cosmological Argument Read the sections on the history of the kalam argument.
- Thomas Aquinas, Summa Theologiae Look in the first part, question 46, on whether the world has always existed.
- William Lane Craig, Reasonable Faith: Christian Truth and Apologetics Read for the modern form of the argument and its debt to the medieval tradition.
- Augustine of Hippo, The City of God Look in Book 11 for Augustine on time and creation.
- Genesis 1 In the beginning.
- John 1 In the beginning was the Word.