What is obscenity? This is an important question because, if the government can ban something "obscene," then that material falls outside the protection of the First Amendment and those who wish to distribute such material will have little, if any, recourse against censorship. Even worse, allegations of obscenity stem almost entirely from religious foundations, which means that essentially religious objections to material can remove basic constitutional protections from that material.
This was two combined cases: Roth v. United States and Alberts v. California.
Roth published and sold books, photographs and magazines in New York, using circulars and advertising matter to solicit sales. He was convicted of mailing obscene circulars and advertising and an obscene book in violation of the federal obscenity statute:
Every obscene, lewd, lascivious, or filthy book, pamphlet, picture, paper, letter, writing, print, or other publication of an indecent character... is declared to be nonmailable matter... Whoever knowingly deposits for mailing or delivery, anything declared by this section to be nonmailable, or knowingly takes the same from the mails for the purpose of circulating or disposing thereof, or of aiding in the circulation or disposition thereof, shall be fined not more than $5,000 or imprisoned not more than five years, or both.
Alberts ran a mail-order business from Los Angeles and was convicted under a misdemeanor complaint which charged him with lewdly keeping for sale obscene and indecent books, and with writing, composing and publishing an obscene advertisement of them, in violation of the California Penal Code:
Every person who wilfully and lewdly... writes, composes, stereotypes, prints, publishes, sells, distributes, keeps for sale, or exhibits any obscene or indecent writing, paper, or book; or designs, copies, draws, engraves, paints, or otherwise prepares any obscene or indecent picture or print; or molds, cuts, casts, or otherwise makes any obscene or indecent figure... is guilty of a misdemeanor...
In both cases the constitutionality of a criminal obscenity statute was challenged. In Roth, the constitutional question was whether the federal obscenity statute violated the provision of the First Amendment that "Congress shall make no law ...abridging the freedom of speech, or of the press ..." In Alberts, the constitutional question was whether the obscenity provisions of the California Penal Code invaded the freedoms of speech and press incorporated by the Due Process Clause of the Fourteenth Amendment.
Voting 5-4, the Supreme Court decided that 'obscene' material has no protection under the First Amendment because freedom of expression does not provide absolute protection for every possible utterance of any sort:
All ideas having even the slightest redeeming social importance - unorthodox ideas, controversial ideas, even ideas hateful to the prevailing climate of opinion - have the full protection of the guaranties, unless excludable because they encroach upon the limited area of more important interests. But implicit in the history of the First Amendment is the rejection of obscenity as utterly without redeeming social importance.
But who decides what is and is not "obscene," and how? Who gets to decide what does and does not have "redeeming social importance," and based on what standard? Some Christians deny that atheism has any redeeming social importance.
Justice Brennan, writing for the majority, suggested a standard for determining what would and would not be obscene:
However, sex and obscenity are not synonymous. Obscene material is material which deals with sex in a manner appealing to prurient interest. The portrayal of sex, e. g., in art, literature and scientific works, is not itself sufficient reason to deny material the constitutional protection of freedom of speech and press. ...It is therefore vital that the standards for judging obscenity safeguard the protection of freedom of speech and press for material which does not treat sex in a manner appealing to prurient interest.
So, there is no "redeeming social importance" to any appeal to prurient interests? This is a traditionalist religious and Christian perspective. There are no legitimate secular arguments for such an absolute division.
The early leading standard of obscenity allowed material to be judged merely by the effect of an isolated excerpt upon particularly susceptible persons. Some American courts adopted this standard but later decisions have rejected it and substituted this test: whether to the average person, applying contemporary community standards, the dominant theme of the material taken as a whole appeals to prurient interest.
Since the lower courts in these cases applied the test of whether or not the material appealed to purient interests, the judgements were affirmed.
This decision specifically rejected the test developed in the British case Regina v. Hicklin, that obscenity is judged by "whether or not the tendency of the matter charged as obscenity is to deprave and corrupt those whose minds are open to such immoral influences, and into whose hands a publication of this sort may fall." So, instead of basing a judgement on how it might influence the most susceptible people, judgement is based on community standards.
In a community of very conservative Christians, a person could be charged with obscenity for expressing ideas that would be regarded as trivial in another community. Thus a person might legally sell explicit homosexual material in the city, but be charged with obscenity in a small town. Conservative Christians could argue that the material has no redeeming social value, but closeted gays could argue the opposite because it helps them imagine what life might be like without homophobic oppression.