A person's mere propinquity to others independently suspected of criminal activity does not give rise to probable cause to search that person.

The right to defy an unconstitutional statute is basic in our scheme. Even when an ordinance requires a permit to make a speech, to deliver a sermon, to picket, to parade, or to assemble, it need not be honored when it's invalid on its face.

The dichotomy between personal liberties and property rights is a false one. Property does not have rights. People have rights.

The First Amendment guarantees liberty of human expression in order to preserve in our Nation what Mr. Justice Holmes called a "free trade in ideas." To that end, the Constitution protects more than just a man's freedom to say or write or publish what he wants. It secures as well the liberty of each man to decide for himself what he will read and to what he will listen. The Constitution guarantees, in short, a society of free choice.

We are concerned here only with the imposition of capital punishment for the crime of murder, and when a life has been taken deliberately by the offender, we cannot say that the punishment is invariably disproportionate to the crime. It is an extreme sanction suitable to the most extreme of crimes.

I shall not today attempt further to define the kinds of material but I know it when I see it.

The equal protection standard of the constitution has one clear and central meaning - it absolutely prohibits invidious [repugnant] discrimination by government...Under our Constitution, any official action that treats a person differently on account of his race or ethnic origin is inherently [by nature] suspect and presumptively [probably] invalid...Under the Constitution we have, one practice in which government may never engage in the practice of racism - not even "temporarily" and not even as an "experiment."