Every civilization has invented the holiday — the holy day — which suggests that every civilization has noticed that continuous work produces a person who is technically alive but not exactly living. Nasreddin took his vacations in the middle of workdays, his holidays whenever he remembered to, and his holy days every morning before the village woke up. The cross-cultural study of rest is, at bottom, a cross-cultural study of what each tradition considers the self to actually need.
Each step builds on the last.