Nihilism is a family of philosophical views arguing that life is meaningless, that moral values are baseless, or that knowledge is impossible. Thus, such views reject the basis of certain ideas. Nihilistic views span several branches of philosophy, including ethics, value theory, epistemology, and metaphysics. Nihilism is also described as a broad cultural phenomenon or historical movement that pervades modernity in the Western world.

Existential nihilism asserts that life is inherently meaningless and lacks a higher purpose. By suggesting that all individual and societal achievements are ultimately pointless, it can lead to indifference, lack of motivation, and existential crises. In response, some philosophers propose detachment from worldly concerns, while others seek to discover or create values. Moral nihilism, a related view, denies the objective existence of morality, arguing that moral evaluations and practices rest on misguided assumptions without any foundation in external reality.

In epistemology or the theory of knowledge, nihilism challenges knowledge and truth. According to relativism, knowledge, truth, or meaning are relative to the perspectives of specific individuals or cultural contexts. This implies that there is no independent framework to assess which opinion is ultimately correct. Skeptical interpretations go further by denying the existence of knowledge or truth altogether. In metaphysics, one form of nihilism states that the universe could have been empty without any objects. This view holds that there is no fundamental reason for why something exists rather than nothing. Mereological nihilism asserts that there are only simple objects, like elementary particles, but no composite objects, like tables. Cosmological nihilism is the view that reality is unintelligible and indifferent to human understanding. Other nihilist positions include political, semantic, logical, and therapeutic nihilism.

Some aspects of nihilism have their roots in ancient philosophy in the form of challenges to established beliefs, values, and practices. However, nihilism is primarily associated with modernity, emerging in the 18th and 19th centuries, particularly in Germany and Russia through the works of Friedrich Heinrich Jacobi and Ivan Turgenev. It took center stage in the thought of Friedrich Nietzsche, who understood nihilism as a pervasive cultural trend in which people lose the values and ideals guiding their lives as a result of secularization. In the 20th century, nihilist themes were explored by Dadaism, existentialism, and postmodern philosophy.

Nihilism is a family of views that reject or deny certain aspects of existence. Different forms of nihilism deny different features of reality. For example, existential nihilism denies that life has a higher meaning, and moral nihilism rejects the existence of moral phenomena. Similarly, epistemological nihilism questions the possibility of objective knowledge, while political nihilism advocates the destruction of established political institutions. The precise definition of nihilism is disputed, and many other definitions and types of nihilism have been proposed, covering a wide range of topics studied by different branches of philosophy, such as ethics, value theory, epistemology, and metaphysics.

In addition to philosophical theories, nihilism can also refer to a broader cultural phenomenon or historical movement. In this context, it is primarily associated with modernity in the Western world, characterized by deep skepticism toward established norms and values alongside indifference, despair, and a lack of purpose. Outside the academic discourse, the term nihilism is used more loosely in everyday language to describe negative, destructive, or antisocial attitudes, expressing that someone fails to care about a particular issue. For instance, conservatives may be labeled as nihilistic for not valuing progress, while progressives may be described as such for disregarding established norms.

Nihilism is closely associated with other disillusioned attitudes toward the world, like pessimism, absurdism, existentialism, cynicism, and apathy. Although the meanings of these terms overlap, they have distinct connotations and do not necessarily imply one another. Pessimism contrasts with optimism as a negative outlook focused on bad outcomes and characterized by hopelessness. A key difference to nihilism, according to one interpretation, is that pessimists see the world as inherently bad, whereas nihilists deny that it has any positive or negative meaning. Absurdism argues that the world is not just meaningless, as existential nihilism asserts, but also absurd. It examines the absurdity arising from paradoxical attempts to find meaning in an inherently meaningless universe. Existentialism is a philosophical tradition that addresses absurdist and nihilist views while exploring the human condition through themes like anxiety, death, freedom, and authenticity. Cynicism is a distrustful attitude toward the motives of other people or society in general. Apathy is a state of mind in which a person does not care about things, characterized by indifference and a lack of desires and emotions.

The word nihilism is a combination of the Latin term nihil, meaning 'nothing', and the suffix -ism, indicating an ideology. Its literal meaning is 'ideology of nothing' or 'ideology of negation', reflected in terms like annihilate and nihility. The word emerged in 18th-century Germany, first as a literary term and later as a philosophical notion, which Friedrich Heinrich Jacobi conceptualized to criticize philosophical thought that rejects meaning or existence. Its first recorded use in English dates to the 1810s. The term became popular in 19th-century Russia through Ivan Turgenev's novel Fathers and Sons and the Russian nihilist movement. Interest in it increased more broadly in the 20th century in response to Friedrich Nietzsche's works, while its meaning expanded to cover a wider range of philosophical and cultural phenomena.