We, then, are the men of practice and of experience; for we oppose to the restriction which you have placed exceptionally on certain international exchanges, the practice and experience of all individuals, and of all agglomerations of individuals, whose acts are voluntary, and can consequently be adduced as evidence. But you begin by _constraining, by hindering_, and then you lay hold of acts which are _forced or prohibited_, as warranting you to exclaim, "We have practice and experience on our side!" You inveigh against our theory, and even against theories in general. But when you lay down a principle in opposition to ours, you perhaps imagine you are not proceeding on theory? Clear your heads of that idea. You in fact form a theory, as we do; but between your theory and ours there is this difference: Our theory consists merely in observing universal _facts_, universal opinions; calculations and ways of proceeding which universally prevail; and in classifying these, and rendering them Co-ordinate, with a view to their being more easily understood. Our theory is so little opposed to practice that it is nothing else but _practice explained_. We observe men acting as they are moved by the instinct of self-preservation and a desire for progress, and what they thus do freely and voluntarily we denominate political or social economy. We can never help repeating, that each individual man is _practically_ an excellent economist, producing or exchanging according as he finds it more to his interest to produce or to exchange. Each, by experience, educates himself in this science; or rather the science itself is only this same experience accurately observed and methodically explained. But on your side, you construct a _theory_ in the worst sense of the word. You imagine, you invent, a course of proceeding which is not sanctioned by the practice of any living man under the canopy of heaven; and then you invoke the aid of constraint and prohibition. It is quite necessary that you should have recourse to _force_, for you desire that men should be made to produce those things which they find it _more advantageous_ to buy; you desire that they should renounce this _advantage_, and act upon a doctrine which implies a contradiction in terms. The doctrine which you acknowledge would be absurd in the relations of individuals; I defy you to extend it, even in speculation, to transaction between families, communities, or provinces. By your own admission, it is only applicable to international relations. This is the reason why you are forced to keep repeating: "There are no absolute principles, no inflexible rules. What is _good_ for an individual, a family, a province, is _bad_ for a nation. What is _good_ in detail--namely, to purchase rather than produce, when purchasing is more advantageous than producing--that same is _bad_ in the gross. The political economy of individuals is not that of nations;" and other nonsense _ejusdèm farino_.