Big Dog and Little Dog Getting in Trouble

I got the whole set for my 30 year old sister who fell in love with the story. The language is simple and very funny. A great buy for dog lovers with a sense of humor.

Big Dog and Little Dog are very lovable, but bad, in the only children's book I know that comes right out and says what all children know--being bad is fun, at least until it's time to pay. This book also may serve as a foundation on which to engage a child on the nature of justice. In particular, is it fair that Big Dog, after creating a big mess, gets in big trouble, while Little Dog, who created only a little mess, also gets in big trouble? Should there not be a principle of proportionality in the imposition of penalties?