The other day my son asked, “Daddy, what is a shadow?”
It turned out to be a harder question to answer than I expected! “Light” is wrong, but “absence of light” isn’t quite right either. After all, you could have an absence of light without a shadow.
A shadow is clearly something, but you can never really grasp it. When Peter Pann loses his shadow, that’s what makes it funny. Even pointing to it literally changes it.
A shadow is an interplay of light and darkness, causes and conditions. Aren’t we all?