Whenever a theory is in contradiction to the welfare of society it is because that theory is false, for society is the supreme truth.
Unquestionably in ordinary times, man is not imprisoned by nature, and ought not to be by the law, within the frontiers of his native land; and, with this view, the laws against emigration should only be exceptional laws.

But, because exceptional, are these laws therefore unjust?
Evidently not.

The public danger has its peculiar laws, as necessary and as just as laws made in a time of security.

A state of war is not a state of peace.

You shut your frontiers to strangers in war time; you may close them to your citizens.