‘For if the bookseller is criminally liable without knowledge of the contents, * * * he will tend to restrict the books he sells to those he has inspected; and thus the State will have imposed a restriction upon the distribution of constitutionally protected as well as obscene literature. * * * And the bookseller’s burden would become the public’s burden, for by restricting him the public’s access to reading matter would be restricted. * * * (H)is timidity in the face of his absolute criminal liability, thus would tend to restrict the public’s access to forms of the printed word which the State could not constitutionally suppress directly. The bookseller’s self-censorship, compelled by the State, would be a censorship affecting the whole public, hardly less virulent for being privately administered. Through it, the distribution of all books, both obscene and not obscene, would be impeded.’ [Cc] A rule compelling the critic of official conduct to guarantee the truth of all his factual assertions-and to do so on pain of libel judgments virtually unlimited in amount-leads to a comparable ‘self-censorship.’ Allowance of the defense of truth, with the burden of proving it on the defendant, does not mean that only false speech will be deterred. Even courts accepting this defense as an adequate safeguard have recognized the difficulties of adducing legal proofs that the alleged libel was true in all its factual particulars. [Cc] Under such a rule, would-be critics of official conduct may be deterred from voicing their criticism, even though it is believed to be true and even though it is in fact true, because of doubt whether it can be proved in court or fear of the expense of having to do so. They tend to make only statements which ‘steer far wider of the unlawful zone.’ [Cc] The rule thus dampens the vigor and limits the variety of public debate. It is inconsistent with the First and Fourteenth Amendments.
The constitutional guarantees require, we think, a federal rule that prohibits a public official from recovering damages for a defamatory falsehood relating to his official conduct unless he proves that the statement was made with ‘actual malice’-that is, with knowledge that it was false or with reckless disregard of whether it was false or not. An oft-cited statement of a like rule, which has been adopted by a number of state courts, is found in the Kansas case of Coleman v. MacLennan, 98 P. 281 (1908). The State Attorney General, a candidate for re-election and a member of the commission charged with the management and control of the state school fund, sued a newspaper publisher for alleged libel in an article purporting to state facts relating to his official conduct in connection with a school-fund transaction.
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On appeal the Supreme Court of Kansas, in an opinion by Justice Burch, reasoned as follows: