In the 1942 case of Spies v. United States, Frederick W. Spies was convicted for willfully attempting to evade and defeat income tax payments under Section 145(b) of the Internal Revenue Code. The Supreme Court upheld his conviction, ruling that a "willful attempt" could be inferred from conduct meant to mislead or conceal. In this case, Spies had failed to file an income tax return and made false statements about his financial status in order to avoid paying taxes on substantial gambling winnings over several years. The court clarified that while not filing a tax return might constitute negligence or even gross negligence (which would fall under another section of the code), it did not necessarily imply fraudulent intent required by Section 145(b). However, when combined with other actions such as making false statements intended at evasion, it can serve as evidence towards proving willfulness. This decision set important precedent for future cases involving tax evasion charges: mere failure to pay taxes does not automatically equate fraudulence; there must be clear intentionality behind evading payment.

In the dissenting opinion for Spies v. United States, Justice Frank Murphy argued that the majority's interpretation of tax evasion laws was too broad and could potentially criminalize innocent mistakes made by taxpayers. He contended that a taxpayer should only be found guilty of felony tax evasion if there is clear evidence they deliberately intended to defraud the government. According to him, merely failing to report income or making an error on a tax return should not automatically constitute fraud unless it can be proven beyond reasonable doubt that these actions were done with fraudulent intent. Furthermore, he expressed concern over how this ruling might impact future cases and urged caution in interpreting such serious offenses so broadly.