This book develops a novel argument which combines the Kalam with the Thomistic Cosmological Argument. It approaches an ongoing dispute concerning whether there is a First Cause of time from a radically new point of view, namely by demonstrating that there is such a First Cause without requiring the controversial arguments against concrete infinities and against traversing an actual infinite (although the book presents original defenses of these arguments as well). This book also develops a novel philosophical argument for the Causal Principle, namely that ‘everything that begins to exist has a cause’, and offers a detailed discussion on whether a First Cause of time can be avoided by a causal loop. It also addresses epistemological issues related to the Cosmological Argument which have been relatively neglected by recent publications, and demonstrates (contra Hawking et al) the continual relevance and significance of philosophy for answering ultimate questions.