by John Marshall Harlan, Smythe v. United States — Opinion of the Court
“ And it is proof of this very fact which is refused on the ground of public policy. Can the government maintain the proposition that if it has suffered in truth no loss it can nevertheless recover either the penalty of the bond or any less sum? This is to change the legal import of the bond. But it is nevertheless maintained that it is against public policy to permit proof of a fact which if it really existed would undoubtedly constitute a defense to the claim made by the government. That kind of a public policy which prevents a legal defense I cannot understand. ”
