First published in 1987, Needs by Garrett Thomson aims to explain the ways in which the concept of a need functions, and an important part of this must be to reveal its distinctive empirical content and show how that content relates to its evaluative role. Thomson examines the distinction between fundamental needs and desires, addressing topics such as human nature, harm, interests, and the limits of choice. Through rigorous analysis, he challenges subjective and objective perspectives on harm and necessity, while investigating the interplay between needs and morality. Featuring a newly added preface for this reissue, this book serves as an indispensable resource for scholars of philosophy, ethics, and human behavior.