"Over and over again courts have said there is nothing sinister in so arranging one's affairs as to keep taxes as low as possible.  Everybody does so, rich or poor; and all do right, for nobody owes any public duty to pay more than the law demands; taxes are enforced exactions, not voluntary contributions.  To demand more in the name of morals is mere cant..."

Judge Learned Hand in Commissioner v. Newman.  159 F.2d 848 (2d Cir. 1947)