This volume explores the use of higher-order logics in metaphysics. Higher-order logics are natural extensions of the common systems of predicate logic, with a history going back to the very beginnings of formal logic. Such logics are well suited to formalize metaphysical views and arguments. Over the last decade, there has been a resurgence of interest in higher-order metaphysics.Seventeen original essays are grouped under five headings. Three introductory chapters present higher-order languages and motivate their use in metaphysics. Three chapters on pure higher-order metaphysics discuss different options of higher-order languages and logics which may be used in metaphysics. Three chapters on applied higher-order metaphysics consider the application of higher-order logic to various central topics of metaphysics. Three historical chapters trace the development of higher-order logic as it relates to metaphysics over the last 150 years. The volume concludes with a discussion, containing two chapters criticizing the use of higher-order logic in metaphysics, as well as responses to these criticisms by two authors.