This is rapidly becoming surreal.

Forbidden is not a fundamental property of the world, it is imposed by theorists with agendas.

Samuelson, Wald, von Neumann, Savage, and the other founders of "revealed preference" forbid us to ask how much Joe (or anything else) is worth, independent of an agent with preferences, such as Mary.

Emmanuel Kant, and anyone else who takes "The categorical imperative" at all seriously, forbids us to ask what Joe is worth to Mary, though we may ask what Joe's cat Maru is worth to Mary.

I knew I shouldn't have gotten involved in this thread.