The cosmological argument in Islam

The Kalam cosmological argument is, historically, an Islamic argument. It took its canonical form in the ninth through eleventh centuries among Muslim mutakallimun — speculative theologians — who needed to defend the Qur'anic doctrine of creation against the Aristotelian view, inherited through Neoplatonic commentators, that the universe is eternal. If the universe had always existed, creation becomes metaphysically empty; the theologians' task was to show, by reason alone, that the universe had a beginning.

al-Kindi, the first major Muslim philosopher, produced an early version arguing that infinite regress of past events is incoherent. al-Ghazali in The Incoherence of the Philosophers (Tahafut al-Falasifa, 1095) gave the definitive statement: whatever begins to exist has a cause; the universe began to exist; therefore the universe has a cause. His arguments against actually infinite pasts — later sharpened by modern philosophers into claims about the impossibility of forming an actual infinite by successive addition — remain the structural core of contemporary Kalam defenses.

Ibn Sina (Avicenna) took a different route in his proof of the Necessary Existent, arguing from the contingency of any possible being to the existence of a being whose essence is existence. This is structurally closer to Leibniz than to al-Ghazali. When William Lane Craig reintroduced the Kalam to English-speaking philosophy of religion in the 1970s, he was reviving — and explicitly crediting — the Islamic tradition. Modern Muslim apologists like Hamza Tzortzis have made the Kalam a centerpiece of da'wah aimed at secular audiences.