When people engage in a commercial transaction, there is a contract, either explicit or implied. The concept of fraud stems from the idea of broken contracts. A

When people engage in a commercial transaction, there is a contract, either explicit or implied. The concept of fraud stems from the idea of broken contracts. Anything other than that is caveat emptor. You're not the person who replied to me about "health" and "happiness," but I'm guessing that even though you'll cry "Who then defines what is fraud?" you have no trouble deciding that "Society" should define health and happiness—yes? Better that we stick to more concrete and prosaic ideas like contract.