Questions Does God exist?The world began, so it has a cause

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The world began, so it has a cause

The kalam argument (al-Ghazali's version)

Al-Ghazali 1058 · 1111Reason has limits: certainty comes from experiencing God.

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What it claims

The world began, it has a cause, and this cause is eternal: it is the Maker of the world.

Why

An infinity of revolutions already elapsed is impossible, so the world began, and whatever begins has a cause.

The same idea through history

Al-Ghazali1095The version presented here, in the Middle Ages: against the philosophers of his day (Avicenna), who hold the world to be eternal. The whole proof rests on the impossibility of an infinity of celestial revolutions already elapsed.

William Lane Craig1979William Lane Craig revived the argument in the 20th century as the "kalam argument". He supports it with the mathematics of infinity (Hilbert's Hotel) and big bang cosmology, and adds that the cause must be a person. The modern debate (Mackie, Oppy, Carroll, Morriston) is presented on his page.

In short

"The world began, so it has a cause" is an argument by Al-Ghazali (al-Iqtisad, I, 1-2 (c. 1095-1096); The Incoherence of the Philosophers, discussion 1, 1095) on the question "Does God exist?" (answer: theism). Its claim: The world began, it has a cause, and this cause is eternal: it is the Maker of the world. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P5). AskPhilosophy presents 5 objections, 4 of them with a documented reply, and the original text behind each premise, checked word for word.

al-Iqtisad, I, 1-2 (c. 1095-1096); The Incoherence of the Philosophers, discussion 1

Valid with an implicit premise

The philosophers of his day, following Aristotle and Avicenna, think the world is eternal: the heavens have always turned, and God is their cause from all eternity, as the sun is the cause of its light. Al-Ghazali argues on the contrary that the world began, and that this is precisely what proves it has a cause. His key idea: if the world had not begun, an infinity of revolutions of the heavens would already have elapsed, and that leads to absurdities. This page presents his version and the debate with the philosophers of his time; the modern version of the argument is Craig's (see "Other versions").

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.

Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P5, the computer finds a world with no beginning, with an infinity of past revolutions that do not form a countable whole: the question "even or odd?" does not arise, and the conclusion fails. This is exactly the philosophers' reply (second objection).

The argument is valid if we add P5, which al-Ghazali does not state in al-Iqtisad but defends in the Incoherence when the philosophers dispute it. Without P5, his absurdities (even or odd, Saturn and the Sun) no longer hold: they only concern numbers that can be counted. The whole debate is therefore about P4 and P5, that is, about infinity. Note: the argument proves an eternal cause; it does not yet say that it chooses. For that, al-Ghazali adds, against the philosophers, that this cause acts through a will (see the first objection).

Analogy. Imagine a queue with no beginning, in which everyone arrived after the person before. For it to reach you, an infinity of people would have had to pass first: the queue could never have "got" to today. For al-Ghazali, past time is that queue: if it had no beginning, today could never have come.

Objections

Each objection is a conversation: click to see who replies and where the debate stands.

Avicenna and the philosophers (as reported by al-Ghazali) 1027 · attacks the conclusion

An eternal cause that is always the same cannot produce a world that begins. If nothing changes in it, why would the world have appeared at one moment rather than before? Either nothing comes from it, or what comes from it has always existed. So the world is eternal, caused by God from all eternity, as light is by the sun.

Al-Ghazali replies

Al-Ghazali

What prevents us from saying that the world began through an eternal will, which willed its existence at the moment it came to exist? Before, its existence was not willed, so it did not exist; at that moment, it was willed by the eternal will, so it came to exist. What is impossible about that?

The philosophers (as reported by al-Ghazali)

But all moments are alike. What distinguishes one particular moment from those before and after it? Nothing is distinguished from its like without something that distinguishes it.

See the rest of the debate (1)

Al-Ghazali

That is precisely the role of the will: it is an attribute whose function is to distinguish a thing from its like. Asking why the will chose one of two like things is like asking why knowledge knows its object: that is what it is.

The debate goes on (our summary) Al-Ghazali adds an example: a man fond of dates, faced with two identical dates, takes one; so he chooses with no reason distinguishing the two. The debate remains open. Averroes would reply that a will that chooses with no reason at all is not a will as we know it. The philosophers add, in the text, that a complete cause produces its effect at once (al-Ghazali reports this argument too). Even today, Morriston makes the same objection to Craig (see the kalam argument).

Where the debate stands (our summary)Al-Ghazali answers that an eternal will can choose one moment among alike moments; Averroes will judge that a will with no reason to choose is not a will. The core disagreement: is a freedom with no sufficient reason intelligible? Craig takes up the idea of a free agent (see his argument).

The philosophers (as reported by al-Ghazali) 1095 · attacks premise 5

Your mistake is to speak of "a whole made of units". Past revolutions no longer exist, and future ones do not yet. A whole means things that are present; here there is nothing. So one cannot ask whether their number is even or odd.

Al-Ghazali replies

Al-Ghazali

A number is necessarily even or odd, whether the things counted still exist or not. If we think of a number of horses, it is even or odd, whether they exist or have perished.

Al-Ghazali

And on your own principles there now exists an infinity of distinct things: human souls separated from the body by death. This is Avicenna's view, and perhaps Aristotle's. Their number is neither even nor odd: what will you answer to someone who says this is an evident absurdity?

The debate goes on (our summary) Each side turns the argument against the other: al-Ghazali calls an infinity that is neither even nor odd absurd, but shows that the philosophers already accept one for souls. Modern mathematics (Cantor, 19th century) would say that an infinite collection is indeed neither "even" nor "odd" in the ordinary sense, without contradiction. Averroes would later reply that the difference is clear to the philosophers: an infinity of bodies existing at the same time is impossible, but an infinite series in time is not an actual infinite; he also denies that Avicenna accepted an infinity of souls (a point historians discuss). The open question is whether such an infinity can exist in real time: that is the heart of the modern debate between Craig, Mackie and Oppy.

Where the debate stands (our summary)Each side turns the argument against the other: an infinity that is neither even nor odd is absurd for al-Ghazali, but the philosophers already accepted one for souls. Modern mathematics (Cantor) makes a completed infinity coherent without saying whether one can exist in the world: an open point.

Objection anticipated by al-Ghazali attacks premise 4

You yourselves accept an infinity: according to you, what God can do is endless, and so is what he knows; and what he knows is larger than what he can do. There is an infinity larger than another infinity, the very absurdity you charge the celestial revolutions with.

Al-Ghazali replies

Al-Ghazali

Saying that God's power is endless does not mean that an infinity of things exists. It means that God can always bring something into being. Things are the existents, and they are finite in number.

The debate goes on (our summary) The reply distinguishes a "potential" infinity (one can always add more) from a "real" infinity (an infinity of things already there). This is Aristotle's distinction, and it is still Craig's. But his opponents answer that the past no longer exists either: would an infinity of past days really be a "real" infinity?

Where the debate stands (our summary)The reply distinguishes a potential infinity from a real one. The disagreement is whether past events, which no longer exist, form a real infinity (see Craig's argument).

Thomas Aquinas 1268 · attacks premise 4

That the world began is known by faith, but reason cannot demonstrate it. The arguments against an infinite past are not demonstrations. That is why Thomas, who himself believed the world began, proves God while supposing, on the contrary, an eternal world: if the proof works even then, it is sounder.

a defender replies

No reply possible: objection raised in 1268, after the author's death (1111).

William Lane Craig defender of the argument · 1979

Summary: Craig argues on the contrary that reason can establish that the past is finite: a real infinity of things cannot exist (Hilbert's Hotel), and a series of events cannot actually be formed by successive addition. He thus takes up Bonaventure's route against Aquinas's.

see the argument

The debate goes on (our summary) Thomas grants al-Ghazali that, if the world began, it obviously needs a cause (Summa contra Gentiles, I, 13). The disagreement is about P4: can reason alone prove that an infinite past is impossible? Bonaventure, at the same time, thought so; Thomas did not.

Where the debate stands (our summary)Aquinas holds that the world's beginning is a matter of faith and that reason does not demonstrate it; Bonaventure, then Craig, argue the opposite. The core disagreement: is an infinite past impossible by reason alone? Neither side has a demonstration accepted by the other.

Averroes 1180 · attacks the conclusion

The quarrel over the eternity of the world is almost a quarrel about words. Theologians and philosophers agree on the essential: the world is produced by God, and it resembles both what begins and what is eternal. So no one should be declared an unbeliever on this point. And, he adds in The Incoherence of the Incoherence, an eternal will choosing a moment with no reason at all is not intelligible.

no reply

No reply possible: objection raised in 1180, after the author's death (1111).

The debate goes on (our summary) Averroes, born after al-Ghazali's death, defends Aristotle and a world created from all eternity. For al-Ghazali it is not a matter of words: an eternal world would not truly need a Creator who chooses, and this is one of the three points on which he judges the philosophers to be outside Islam.

Where the debate stands (our summary)Averroes judges the quarrel almost verbal; for al-Ghazali, an eternal world would not truly need a Creator who chooses. The core disagreement is the meaning of "create": an open debate, with no reply from al-Ghazali to Averroes, who came after him.

What today's voices say

Defend it

Mohammed HijabHe treats the necessary-versus-contingent argument as stronger than arguments that rest on the universe having a beginning, because it holds whether or not the universe is eternal.

In the same family · Cosmological