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A Boy and a Girl are in the playground. The Boy pinches the Girl's arm. The Girl cries.
Meta: Did the Boy cause the Girl's cries by pinching her arm?
The Boy pinches her again and the Girl cries.
Meta: How many times would the Boy need to pinch the Girl to confirm that pinching causes the Girl's cries?
The Boy pinches the Girl again. She did not cry.
Meta: Did the pinch stop causing the cries?
The Boy pinches the Girl again. She cries.
Meta: Does pinching cause the Girl's cries? How would you distinguish either case?
Causality is a pattern of events in sequence, stable under recurrence, within a declared observational scale (time, space, complexity, or other). It is a relation between a sequence of events and their observation. Causality cannot be asserted without declaring the scale.