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Your search for What is existentialism in simple terms returned the following results:

the belief I must have until there is any evidence of the alternative

Existentialism is the belief I must have until there is any evidence of the alternative.

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a humanism [L’existentialisme est un humanisme]

Existentialism is a humanism [L’existentialisme est un humanisme].

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the idea that 'existence precedes essence,' ie, that one is born without a purpose

Existentialism is the idea that 'existence precedes essence,' ie, that one is born without a purpose.

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the attempt to think about and give expression to the 'human condition' from the supposition that human existence has no intrinsic meaning, purpose or value

‘Existentialism’ is the attempt to think about and give expression to the 'human condition' from the supposition that human existence has no intrinsic meaning, purpose or value.

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a philosophy that advocates that people recognize the reality of human existence

Existentialism is a philosophy that advocates that people recognize the reality of human existence.

a philosophy that stresses the meaninglessness of existence and the importance of the individual in searching for moral values in an uncertain world

Existentialism is a philosophy that stresses the meaninglessness of existence and the importance of the individual in searching for moral values in an uncertain world.

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a philosophical ponder about the self’s existence

Existentialism is a philosophical ponder about the self’s existence.

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a philosophical movement in which individual human beings are understood as having full responsibility for creating the meanings of their own lives

Existentialism could be defined as “Existentialism is a philosophical movement in which individual human beings are understood as having full responsibility for creating the meanings of their own lives.

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nothing but our ability to create and shape our life

Existentialism, in life's essence, is nothing but our ability to create and shape our life.

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a philosophy that recognizes the despair and absurdity of human existence and offers a way of coping with a way

Existentialism is a philosophy that recognizes the despair and absurdity of human existence and offers a way of coping with a way .