What do you do with the fact that your seriousness is optional?
What it argues
Absurdity arises when we take our lives seriously and can also step back and see that seriousness as arbitrary. Nagel argues this is not a problem to solve but a structural feature of self-consciousness, to be met with irony rather than despair or faith.
The probe
Write the strongest case against your most important project, at full strength, as if you believed it. Then note what survives.
The source
The Absurd — Thomas Nagel, 1971. The link goes to the text or to a catalogue record for it, not to a summary. This one is the text itself.