But, on the other hand, it must be stated that what is known, in the broad yet specific sense which is here followed, as Mercantilism, has always had much the same general aim ; it has always rested upon much the same general principles, though one or other of these has been neglected or specially emphasized in ·different periods and in different countries ; and whilst there has been an adaptive variation of means, these have always shown a strong family resemblance, by reason of their relation to the general aim and principles. Hence we may fitly speak of the policy as a "system," on the understanding that the word is not to be taken as pointing to a rigid, undeveloping body of rules and practices.