A nihilist believes that life is meaningless and the only known truth is the existence of the self. An existentialist believes that life is meaningless too, but that meaning can be created by the individual.

By promoting self-awareness and introspection, existentialism encourages people to question societal norms and expectations, fostering a more critical and reflective society. It also highlights the importance of authenticity and living in accordance with one's true self, which can lead to greater personal fulfillment and a deeper sense of purpose.

The term "existentialism" was coined by Gabriel Marcel in the mid-1940s, initially applied to Jean-Paul Sartre, who later embraced the label. Sartre's adoption of existentialism marked a pivotal moment in its development, emphasizing the idea that "existence precedes essence," meaning that individuals are free to create their own meaning in life through their choices and actions. Existentialism is characterized by its focus on the individual's concrete and problematic existence in the world, emphasizing the importance of personal freedom, individual responsibility, and deliberate choice in the pursuit of self-discovery and the determination of life's meaning

Mortality and Death: The awareness of one's mortality or the death of a loved one can prompt existential questioning about the nature of life and the inevitability of death.

Life Transitions: Major life changes such as graduation, career shifts, marriage, divorce, or retirement can lead individuals to reevaluate their goals.

Isolation and Loneliness: lack of meaningful connections with others can lead individuals to question the purpose and significance of their existence.

Questioning Faith: A crisis of faith or the abandonment of previously held religious or philosophical beliefs can leave individuals feeling adrift and questioning the meaning of life.

Failure and Disappointment: Experiencing setbacks, failure, or disillusionment with one's achievements can lead to existential questioning about the value and purpose of striving for success.

Philosophical Pondering and discussions: Intense debates and discussions of existential questions such as the meaning of life, free will, and the nature of reality can provoke existential crises as individuals confront the inherent uncertainties and complexities of existence.

Global Issues and Existential Threats: Concerns about global issues such as climate change, political instability, economic inequality, or existential threats like pandemics or nuclear warfare can evoke feelings of existential dread and insignificance in the face of larger forces beyond individual control.

Midlife Reflection: Midlife often prompts individuals to reflect on their accomplishments, relationships, and mortality, leading to existential questioning about the purpose and direction of their lives.

Existential Literature and Art: Exposure to existential themes in literature, art, or media can prompt individuals to confront existential questions and provoke existential crises as they grapple with the ideas presented.