You need, indeed, have recourse to _force_, since, in wishing that men should _produce_ that which it would be more advantageous to them to _buy_, you wish them to renounce an _advantage_; you demand that they should act in accordance with a doctrine which implies contradiction even in its terms.
Now, this doctrine, which, you argue, would be absurd in individual relations, we defy you to extend, even in speculation, to transactions between families, towns, counties, states.

By your own avowal, it is applicable to international relations only.
And this is why you are obliged to repeat daily: "Principles are not in their nature absolute.

That which is _well_ in the individual, the family, the county, the state, is _evil_ in the nation.

That which is _good_ in detail--such as, to purchase rather than to produce, when purchase is more advantageous than production--is bad in the mass.

The political economy of individuals is not that of nations," and other rubbish, _ejusdem farinae_.