Timothy Leary, a celebrated 1960s connoisseur of mind-altering substances, was found in possession of marijuana and convicted of (1) failure to pay the federal marijuana tax; and (2) transportation and concealment of marijuana, knowing it had been illegally imported into the country. A unanimous Supreme Court held both convictions unconstitutional. Paying the tax would have incriminated Leary under state law; his omission to pay was justified by his RIGHT AGAINST SELF-INCRIMINATION. His other conviction had rested on a statutory presumption that a person in possession of marijuana knew it had been illegally imported. This presumption was irrational; much
marijuana was grown in the United States. The...