I. Meaning of Kalam
Merriam-Webster defines "kalam" (Arabic) as "Islamic scholastic theology."
Kalam is "a school of philosophical theology originating in the 9th century a.d., asserting the existence of God as a prime mover and the freedom of the will" (dictionary.com).
One formulation of the Kalam Cosmological Argument (KCA):
1) If the universe came into being, God brought it into being.
2) The universe came into being.
3) Therefore, God brought the universe into being.
The KCA was developed by Arabic thinkers and scholars of the church. One Arabic (Muslim) name connected with the Kalam argument is Al-Ghazali (ca. 1058/9-1111 CE).
Al-Ghazali was a notable professor of Baghdad, who also influenced the Sufi movement (a mystical version of Islam) and gave it some credence (Michael Molloy). This Muslim thinker employed Greek philosophy (chiefly logic) for apologetical reasons: he wanted to defend Islam by the use of reason. See The Columbia History of Western Philosophy. For the purposes of this discussion, it's important to remember that Al-Ghazali figures into the KCA.
William Lane Craig's work on the subject equally has commanded wide-ranging attention. See https://books.google.com/books?id=coZKAwAAQBAJ&printsec=frontcover&dq=craig+kalam+argument&hl=en&sa=X&ved=0ahUKEwi18KLxs_TbAhUIbq0KHWPPAtIQ6AEIKTAA#v=onepage&q=craig%20kalam%20argument&f=false
III. Premises of Ghazali's Argument and the Actual Infinite
Al-Ghazali's argument seems to rest upon the premise found in Aristotle that an actual quantitative infinite cannot exist. If the universe always existed and did not have a cause, then it would be an actual quantitative infinite. However, Al-Ghazali rejects such reasoning:
"Ghazali frames his argument simply: 'Every being which begins has a cause for its beginning; now the world is a being which begins; therefore, it possesses a cause for its beginning.'" (William Lane Craig)
Craig frames the KCA thus:
1. Whatever begins to exist has a cause. (P1)
2. The universe began to exist. (P2)
3. Therefore, the universe has a cause. (C)
The argument is formally valid since the conclusion (C) follows deductively from the argument's premises. Whether the argument is sound (both formally valid and true) is hotly debated by theists and atheists and probably some agnostics. It is not my purpose to adjudicate the merits of the KCA: I find it compelling, but know many objections have been lodged against it. I merely want to introduce blog readers to this classical argument for God's existence and shed light on Al-Ghazali's significant contribution to the argument.
IV. Summary of Argument
Among writers that discuss the KCA, Hal Flemings' discussion is worth considering. Consult the sources below.
I have given a brief version of the Kalam Cosmological Argument (KCA), a line of reasoning that is compelling to me.
To conclude, some Arabic philosophers of the Middle Ages along with church thinkers reasoned that 1) The universe either had a beginning or did not have a beginning; 2) If the universe began to exist, its existence was either caused or uncaused, and 3) The cause of the universe's existence was either personal or impersonal.
J.P. Moreland and William Lane Craig have argued (based on modern scientific evidence and the seeming impossibility of an extensive or quantitative infinite) that the universe did begin to exist. Therefore, since it appears everything that begins to exist has a cause, then the universe must have a cause and its cause is likely personal.
Sources for Further Reading (Intermediate to Advanced Level):
Craig, William Lane. The Kalam Cosmological Argument. Wipf and Stock, 2007.
Flemings, Hal. A Philosophical, Scientific and Theological Defense for the Notion That a God Exists. Lanham, Md: University Press of America, 2004.
Ghazali, Al. The Incoherence of the Philosophers. Brigham Young University Press, 2000.
Nowacki, Mark R. The Kalam Cosmological Argument for God. Amherst: Prometheus Books, 2007.
Wolfson, Harry Austryn. The Philosophy of the Kalam. Cambridge, Mass: Harvard University Press, 1976.