>> everything in moderation

Saying this is like saying 'pick the optimum point' without saying anything about how to find the optimum point. This cannot be a law, it is the definition of optimum.

Note that optimum point need not be somewhere in the middle or 'inside', like a maxima. The optimum point could very well be on an extreme of the domain (input variables space).

Counterpoint: "everything in moderation, including moderation"