Friedrich Nietzsche’s well-known reputation as a philosophical provocateur is partly the result of his commitment to disabusing his readers of a variety of beliefs: their beliefs in a higher purpose, in an afterlife, in disinterested knowledge, in the absolute value of ‘virtues’ such as compassion, and more. But he does not reject these beliefs merely because he believes they are false (he does) or because he hopes to disrupt the dominant belief system in 19th-century Europe (he does). He rejects these beliefs because he thinks they constitute a clear and present danger to his readers. Such beliefs not only deny life and devalue human existence, they also imperil our psychological wellbeing. To understand why he thinks so requires us to understand his diagnosis of these beliefs as nihilistic.