Epistemology is the explanation of how we think. It is required in order to be able to determine the true from the false, by determining a proper method of evaluation. It is needed in order to use and obtain knowledge of the world around us. This book attempts to provide a systematic overview of the epistemological problems that several questions may raise and focus in some depth on issues relating to the structure and the limits of knowledge and justification. While this book provides an overview of the important issues, it leaves the most basic questions unanswered; as such epistemology will continue to be an ever-expanding area of philosophical discussion as long as questions remain.