Necessary Existence breaks ground on one of the deepest questions anyone ever asks: why is there anything? The classic answer is in terms of a necessary foundation. Yet, why think that is the correct answer? Pruss and Rasmussen present an original defence of the hypothesis that there is a concrete necessary being capable of providing a foundation for the existence of things. They offer six main arguments divided into six chapters. The first argument is an up-to-date presentation and assessment of a traditional causal-based argument from contingency. The next five arguments are new " arguments that make use of twentieth century advances in modal logic. The arguments present possible pathways to an intriguing and far-reaching conclusion. The final chapter answers the most challenging objection to the existence of necessary things. Other books on the subject focus almost exclusively on critiquing or revitalizing one or more traditional cosmological or ontological arguments. Or they engage in examining the latest arguments for a distinctively theistic explanation of contingent reality. Pruss and Rasmussen develop entirely new lines of inquiry. And they appeal to a broader audience by relating the question to contemporary issues in cosmology and ontology, without proposing or critiquing a particular theological perspective. Their book will be of value to anyone whose interests intersect with the classic issue of necessary existence.