This book assesses some of the main forms of the Kalam cosmological argument. The author grapples with both medieval and contemporary interrogations of the argument with reference to Greek, Enlightenment and Medieval philosophers. It gives the reader an insight into some of the main areas of controversy (for example discussions of infinity and contingency) and attempts to make critical assessments throughout. The book concludes with the author’s understanding of the ‘strongest forms’ which attempt to postulate the most undercutting arguments for the existence of God.