In this paper we contemplate the debate, happened in Britain during the second decade of the eighteenth century, over the possibility of a general shortage of demand, in order to identify its common ground with the controversy that, a hundred years later, would give birth to the Law of Markets. To begin with, we go back to the discussion about parsimony and sumptuous consumption that took place within the mercantilist thought. After that, we examine Bernard Mandeville?s economic conception on vices and virtue, especially with regard to the conditions surrounding the stability of purchasing power. Subsequently, the criticisms from George Bluet, Francis Hutcheson and Bishop Berkeley against Mandeville?s ideas are analyzed, as well as their respective proposals to the problem of an insufficiency of demand. Finally, we evaluate in what extent the debate anticipated the contents of some crucial propositions of the classical school.