Censorship is the suppression of speech, public communication, or other information. This may be done on the basis that such material is considered objectionable, harmful, sensitive, or "inconvenient". Censorship can be conducted by governments, private institutions and other controlling bodies.
Governments and private organizations may engage in censorship. Other groups or institutions may propose and petition for censorship. When an individual such as an author or other creator engages in censorship of their own works or speech, it is referred to as self-censorship. General censorship occurs in a variety of different media, including speech, books, music, films, and other arts, the press, radio, television, and the Internet for a variety of claimed reasons including national security, to control obscenity, pornography, and hate speech, to protect children or other vulnerable groups, to promote or restrict political or religious views, and to prevent slander and libel.
Direct censorship may or may not be legal, depending on the type, location, and content. Many countries provide strong protections against censorship by law, but none of these protections are absolute and frequently a claim of necessity to balance conflicting rights is made, in order to determine what could and could not be censored. There are no laws against self-censorship.
In 399 BC, Greek philosopher, Socrates, while defying attempts by the Athenian state to censor his philosophical teachings, was accused of collateral charges related to the corruption of Athenian youth and sentenced to death by drinking a poison, hemlock.
The details of Socrates's conviction are recorded by Plato as follows. In 399 BC, Socrates went on trial and was subsequently found guilty of both corrupting the minds of the youth of Athens and of impiety (asebeia, "not believing in the gods of the state"), and as a punishment sentenced to death, caused by the drinking of a mixture containing hemlock.
Socrates' student, Plato, is said to have advocated censorship in his essay on The Republic, which opposed the existence of democracy.