The Mismeasure of the Self is dedicated to vices that blight many lives. They are the vices of superiority, characteristic of those who feel entitled, superior and who have an inflated opinion of themselves, and those of inferiority, typical of those who are riddled with self-doubt and feel inferior. Arrogance, narcissism, haughtiness, and vanity are among the first group. Self-abasement, fatalism, servility, and timidity exemplify the second. This book shows these traits to be to vices of self-evaluation and describes their pervasive harmful effects in some detail. Even though the influence of these traits extends to any aspect of life, the focus of this book is their damaging impact on the life of the intellect. Tanesini develops and defends a view of these vices that puts vicious motivations at their core. The analyses developed in this work build on empirical research in attitude psychology and on philosophical theories in virtue ethics and epistemology. The book concludes with a positive proposal for weakening vice and promoting virtue.