Taxpayers have the right to decrease the amount of their taxes or to avoid them altogether by means which the law permits. However, a business reorganization must have economic substance in order to affect tax liability. Decided January 7, 1935 (argued 1934). Opinion of the Court: George Sutherland → go there Topic: Businesses/Corporations/Contracts. Gregory v. Helvering, 293 U.S. 465 (1935), was a landmark decision by the United States Supreme Court concerned with U.S. income tax law. The case is cited as part of the basis for two legal doctrines: the business purpose doctrine and the doctrine of substance over form. The business purpose doctrine is essentially that if a transaction has no substantial business purpose other than the avoidance or reduction of Federal tax, the tax law will not regard the transaction. The doctrine of substance over form is essentially that for Federal tax purposes, a taxpayer is bound by the economic substance of a transaction if the economic substance varies from its legal form. Wiki link