This is an introductory book to path integral methods in ?eld theories. It is aimed at graduate students and physicists who need a working knowledge of ?eld theory and its methods for applications in hadron, particle and nuclear physics. While teaching ?eld theory courses over the years I have found that many books on ?eld theory present the path integral methods used in only a very recipe-like way. On the other hand, specialized books on path integrals often contain many more details than are actually needed by non-specialists. I hope that this book here ?lls the gap. It provides enough...