Me. Justice Blackmun
delivered the opinion of the Court. In Miller v. California, 413 U. S. 15 (1973), this Court rejected a plea for a uniform national standard as to what [293] appeals to the prurient interest and as to what is patently offensive; the Court held, instead, that these essentially were questions of fact to be measured by contemporary standards of the community. Id., at 30-34. The instant case presents the issue of the constitutional effect of state law that leaves unregulated the distribution of obscene material to adults, on the determination of contemporary community standards in a prosecution under 18 U. S. C. § 1461 for a mailing that is wholly intrastate. The case also raises the question whether § 1461 is unconstitutionally vague as applied in these circumstances, and the question whether the trial court, during the voir dire of prospective jurors, correctly refused to ask proffered questions relating to community standards.
I
Between February and October 1974 petitioner, Jerry Lee Smith, knowingly caused to be mailed various materials from Des Moines, Iowa, to post office box addresses in Mount Ayr and Guthrie Center, two communities in southern Iowa. This was done at the written request of postal inspectors using fictitious names. The materials so mailed were delivered through the United States postal system to the respective postmasters serving the addresses. The mailings consisted of (1) issues of “Intrigue” magazine, depicting nude males and females engaged in masturbation, fellatio, cunnilingus, and sexual intercourse; (2) a film entitled “Lovelace,” depicting a nude male and a nude female engaged in masturbation and simulated acts of fellatio, cunnilingus, and sexual intercourse ; and (3) a film entitled “Terrorized Virgin,” depicting two nude males and a nude female engaged in fellatio, cunnilingus, and sexual intercourse.
II
For many years prior to 1974 the statutes of Iowa made it a misdemeanor to sell or offer to sell or to give away “any obscene, lewd, indecent, lascivious, or filthy book, pamphlet, [294] paper, . . . picture, photograph, writing . . .” or to deposit in any post office within Iowa any article of that kind. Iowa Code §§ 725.5 and 725.6 (1973).
In 1973, however, the Supreme Court of Iowa, in response to the standards enunciated in Miller v. California, supra, unanimously held that a related and companion Iowa statute, § 725.3 of the 1973 Code, prohibiting the presentation of any obscene or immoral drama, play, exhibition, or entertainment, was unconstitutionally vague and overbroad. State v. Wedelstedt, 213 N. W. 2d 652.1 Wedelstedt, at least by implication — and we so assume — invalidated §§ 725.5 and 725.6 as well.
On July 1, 1974, Laws of Iowa 1974, cc. 1267 and 1268, became effective. These specifically repealed §§ 725.3, 725.5, and 725.6 of the 1973 Code. In addition, however, c. 1267 (thereafter codified as the first 10 sections of c. 725 of the 1975 Iowa Code) defined, among other things, “obscene material,” and made it “a public offense” to disseminate obscene material to minors (defined as persons “under the age of eighteen”). Dissemination of obscene material to adults was not made criminal or even proscribed. Section 92 of c. 1267 (now § 725.9 of the 1975 Code) insured that the law would be applied uniformly throughout the State, and that no lesser [295] governmental unit would impose more stringent regulations on obscene material.
In 1976, the Iowa Legislature enacted a “complete revision” of the State’s “substantive criminal laws.” This is entitled the “Iowa Criminal Code” and is generally effective January 1, 1978. The existing definition of “obscene mate-' rial” remains unchanged, but a new provision, § 2804 of the Criminal Code, Iowa Code Ann. (Spec. Pamphlet 1977), although limited in scope, applies by its terms to adults. It reads:
“Any person who knowingly sells or offers for sale material depicting a sex act involving sado-masochistic abuse, excretory functions, a child, or bestiality which the average adult taking the material as a whole in applying contemporary community standards would find that it appeals to the prurient interest and is patently offensive; and the material, taken as a whole, lacks serious literary, scientific, political, or artistic value shall, upon conviction be guilty of a simple misdemeanor.”
In summary, therefore, we have in Iowa (1) until 1973 state statutes that proscribed generally the dissemination of obscene writings and pictures; (2) the judicial nullification of some of those statutory provisions in that year for reasons of overbreadth and vagueness; (3) the enactment, effective July 1, 1974, of replacement obscenity statutes restricted in their application to dissemination to minors; and (4) the enactment in 1976 of a new Code, effective in 1978, with obscenity provisions, somewhat limited in scope, but not restricted in application to dissemination to minors.
Petitioner’s mailings, described above and forming the basis of his federal prosecution, took place in 1974, after the theretofore existing Iowa statutes relating to obscene material had been nullified by Wedelstedt, but obviously before the 1976 legislation imposing misdemeanor liability with respect to certain transactions with adults becomes effective. Because [296] there is no contention that the materials petitioner mailed went to any minor, the 1974 legislation has no application to his case. And the 1976 legislation, of course, has no effect on petitioner’s criminal liability. Cf. Marks v. United States, 430 U. S. 188 (1977).
Thus, what petitioner did clearly was not a violation of state law at the time he did it. It is to be observed, also, that there is no suggestion that petitioner’s mailings went to any nonconsenting adult or that they were interstate.
Ill
Petitioner was indicted on seven counts of violating 18 U. S. C. § 1461, which prohibits the mailing of obscene materials.3 He pleaded not guilty. At the start of his trial petitioner proposed and submitted six questions for voir dire 4 [297] The court accepted in substance and utilized the first question; this was designed to reveal whether any juror was connected with an organization devoted to regulating or banning obscene materials. The court declined to ask the other five. One of the questions made inquiry as to whether the jurors had any knowledge of contemporary community standards in the Southern District of Iowa with regard to the depiction of sex and nudity. Two sought to isolate the source of the jurors’ knowledge and their understanding of those standards. The remaining two would have explored the jurors’ knowledge of Iowa law on the subject.
At the trial the Government introduced into evidence the actual materials covered by the indictment. It offered nothing else on the issue of obscenity vel non. Petitioner did not testify. Instead, in defense, he introduced numerous sexually explicit materials that were available for purchase at “adult” bookstores in Des Moines and Davenport, Iowa, several advertisements from the Des Moines Register and Tribune, and a copy of what was then c. 725 of the Iowa Code, prohibiting the dissemination of “obscene material” only to minors. At the close of the Government’s case, and again at the close of all the evidence, petitioner moved for a directed verdict of acquittal on the grounds, inter alia, that the Iowa obscenity statute, proscribing only the dissemination of obscene materials to minors, set forth the applicable community standard, and that the prosecution had not proved that the materials at issue offended that standard.
The District Court denied those motions and submitted the case to the jury. The court instructed the jury that contemporary community standards were set by what is in fact [298] accepted in the community as a whole. In making that determination, the jurors were entitled to draw on their own knowledge of the views of the average person in the community as well as the evidence presented as to the state law on obscenity and as to materials available for purchase. App. 22-23.
The jury found petitioner guilty on all seven counts. He was sentenced to concurrent three-year terms of imprisonment, all but three months of which were suspended, and three years’ probation.
In his motion for a new trial, petitioner again asserted that Iowa law defined the community standard in a § 1461 prosecution. In denying this motion, the District Court held that § 1461 was “a federal law which neither incorporates nor depends upon the laws of the states,” App. 33; the federal policy was simply different in this area. Furthermore, the court observed, Iowa’s decision not to regulate distribution of obscene material did not mean that the people of Iowa necessarily “approve[d] of the permitted conduct,” ibid.; whether they did was a question of fact for the jury. The court rejected petitioner’s argument that it was error not to ask the jurors the question about the extent of their knowledge of contemporary community standards. It held that the jurors were entitled to draw on their own knowledge; voir dire on community standards would be no more appropriate than voir dire on the jurors’ concept of “reasonableness.” The court refused to hold that the Government was required to introduce evidence on a community standard in order to sustain its burden of proof. The materials introduced “can and do speak for themselves.” Id., at 34. The court did not address petitioner’s vagueness point.5
The United States Court of Appeals for the Eighth Circuit, [299] by per curiam opinion, agreed with the District Court that the questions submitted by petitioner on community standards, except for the first, were impermissible, since they concerned the ultimate question of guilt or innocence rather than juror qualification. The court noted, however, that it was not holding that no questions whatsoever could be asked in that area. With respect to the effect of state law, the court held that the issue of offense to contemporary community standards was a federal question, and was to be determined by the jury in a federal prosecution. The court noted the admission of Iowa’s obscenity statute into evidence but stated that this was designed to give the jury knowledge of the State’s policy on obscenity when it determined the contemporary community standard. The state policy was not controlling, since the determination was for the jury. The conviction, therefore, was affirmed.
We granted certiorari in order to review the relationship between state legislation regulating or refusing to regulate the distribution of obscene material, and the determination of contemporary community standards in a federal prosecution. 426 U. S. 946 (1976).
IV
The “basic guidelines” for the trier of fact in a state obscenity prosecution were set out in Miller v. California in the form of a three-part test:
“(a) whether ‘the average person, applying contemporary community standards’ would find that the work, taken as a whole, appeals to the prurient interest . . . ; (b) whether the work depicts or describes, in a patently offensive way, sexual conduct specifically defined by the applicable state law; and (c) whether the work, taken as a whole, lacks serious literary, artistic, political, or scientific value.” 413 U. S., at 24 (citations omitted).
In two companion cases, the Court held that the Miller standards were equally applicable to federal legislation. United [300] States v. 12 200-ft. Reels of Film, 413 U. S. 123, 129-130 (1973) (importation of obscene material, 19 U. S. C. § 1305 (a)); United States v. Orito, 413 U. S. 139, 145 (1973) (movement of obscene material in interstate commerce, 18 U. S. C. § 1462). In Hamling v. United States, 418 U. S. 87 (1974), it held, specifically, that the Miller standards applied in a § 1461 prosecution.
The phrasing of the Miller test makes clear that contemporary community standards take on meaning only when they are considered with reference to the underlying questions of fact that must be resolved in an obscenity case.6 The test [301] itself shows that appeal to the prurient interest is one such question of fact for the jury to resolve. The Miller opinion indicates that patent offensiveness is to be treated in the same way. 413 U. S., at 26, 30. See Hamling v. United States, 418 U. S., at 104-105.7 The fact that the jury must measure patent offensiveness against contemporary community standards does not mean, however, that juror discretion in this area is to go unchecked. Both in Hamling and in Jenkins v. Georgia, 418 U. S. 153 (1974), the Court noted that part (b) of the Miller test contained a substantive component as well. The kinds of conduct that a jury would be permitted to label as “patently offensive” in a § 1461 prosecution are the “hard core” types of conduct suggested by the examples given in Miller,8 See Hamling v. United States, 418 U. S., at 114; cf. Jenkins v. Georgia, 418 U. S., at 160-161. Literary, artistic, political, or scientific value, on the other hand, is not discussed in Miller in terms of contemporary community standards. See generally F. Schauer, The Law of Obscenity 123-124 (1976).
The issue we must resolve is whether the jury’s discretion to determine what appeals to the prurient interest and what is patently offensive is circumscribed in any way by a state statute such as c. 725 of the Iowa Code. Put another way, [302] we must decide whether the jury is entitled to rely on its own knowledge of community standards, or whether a state legislature (or a smaller legislative body) may declare what the community standards shall be, and, if such a declaration has been made, whether it is binding in a federal prosecution under § 1461.
[301] “(a) Patently offensive representations or descriptions of ultimate sexual acts, normal or perverted, actual or simulated.
“(b) Patently offensive representations or descriptions of masturbation, excretory functions, and lewd exhibition of the genitals.” 413 U. S., at 25.
[302] Obviously, a state legislature would not be able to define contemporary community standards in a vacuum. Rather, community standards simply provide the measure against which the jury decides the questions of appeal to prurient interest and patent offensiveness. In Hamling v. United States, the Court recognized the close analogy between the function of “contemporary community standards” in obscenity cases and “reasonableness” in other cases:
“A juror is entitled to draw on his own knowledge of the views of the average person in the community or vicinage from which he comes for making the required determination, just as he is entitled to draw on his knowledge of the propensities of a 'reasonable’ person in other areas of the law.” 418 U. S., at KFH05.
It would be just as inappropriate for a legislature to attempt to freeze a jury to one definition of reasonableness as it would be for a legislature to try to define the contemporary community standard of appeal to prurient interest or patent offensiveness, if it were even possible for such a definition to be formulated.
This is not to say that state legislatures are completely foreclosed from enacting laws setting substantive limitations for obscenity cases. On the contrary, we have indicated on several occasions that legislation of this kind is permissible. See Hamling v. United States, 418 U. S., at 114; Miller v. California, 413 U. S., at 25. State legislation must still define the kinds of conduct that will be regulated by the State. For example, the Iowa law in effect at the time this prosecution was instituted was to the effect that no conduct aimed at [303] adults was regulated.9 At the other extreme, a State might seek to regulate all the hard-core pornography that it constitutionally could. The new Iowa law, which will regulate only material “depicting a sex act involving sado-masochistic abuse, excretory functions, a child, or bestiality,” provides an example of an intermediate approach. Iowa Criminal Code § 2804.
If a State wished to adopt a slightly different approach to obscenity regulation, it might impose a geographic limit on the determination of community standards by defining the area from which the jury could be selected in an obscenity case, or by legislating with respect to the instructions that must be given to the jurors in such cases. In addition, the State might add a geographic dimension to its regulation of obscenity through the device of zoning laws. Cf. Young v. American Mini Theatres, Inc., 427 U. S. 50 (1976). It is evident that ample room is left for state legislation even though the question of the community standard to apply, when appeal to prurient interest and patent offensiveness are considered, is not one that can be defined legislatively.
An even stronger reason for holding that a state law regulating distribution of obscene material cannot define contemporary community standards in the case before us is the simple fact that this is a federal prosecution under § 1461. The Court already has held, in Hamling, that the substantive conduct encompassed by § 1461 is confined to “the sort of 'patently offensive representations or descriptions of that specific “hard core” sexual conduct given as examples in Miller v. California.’ ” 418 U. S., at 114. The community standards aspects of § 1461 likewise present issues of federal law, upon which a state statute such as Iowa’s cannot have con-[304] elusive effect.10 The kinds of instructions that should be given to the jury are likewise a federal question. For example, the Court has held that § 1461 embodies a requirement that local rather than national standards should be applied.11 Hamling v. United States, supra. Similarly, obscenity is to be judged according to the average person in the community, rather than the most prudish or the most tolerant. Hamling v. United States, supra; Miller v. California, supra; Roth v. United States, 354 U. S. 476 (1957). Both of these substantive limitations are passed on to the jury in the form of instructions.
[305] The fact that the mailings in this case were wholly intrastate is immaterial for a prosecution under § 1461. That statute was one enacted under Congress’ postal power, granted in Art. I, § 8, cl. 7, of the Constitution, and the Postal Power Clause does not distinguish between interstate and intrastate matters. This Court consistently has upheld Congress’ exercise of that power to exclude from the mails materials that are judged to be obscene. See, e. g., Ex parte Jackson, 96 U. S. 727, 736 (1878); Public Clearing House v. Coyne, 194 U. S. 497, 507-508 (1904) (power to exclude from the mail “information of a character calculated to debauch the public morality”); Roth v. United States, supra; United States v. Reidel, 402 U. S. 351 (1971). See also In re Rapier, 143 U. S. 110 (1892).12
Our decision that contemporary community standards must be applied by juries in accordance with their own understanding of the tolerance of the average person in their community does not mean, as has been suggested, that obscenity convictions will be virtually unreviewable. We have stressed before that juries must be instructed properly, so that they consider the entire community and not simply their own subjective, reactions, or the reactions of a sensitive or of a callous minority. See Miller v. California, 413 U. S., at 30. The type -of conduct depicted must fall within the substantive limitations suggested in Miller and adopted in Hamling with respect to § 1461. Cf. Jenkins v. Georgia, 418 U. S. 153 (1974). The work also must lack serious literary, artistic, political, or scientific value before a conviction will be upheld; this determination is particularly amenable to appellate review. Finally, it [306] is always appropriate for the appellate court to review the sufficiency of the evidence. Cf. Ginzburg v. United States, 383 U. S. 463 (1966).
Petitioner argues that a decision to ignore the Iowa law will have the practical effect of nullifying that law. We do not agree. In the first place, the significance of Iowa’s decision in 1974 not to regulate the distribution of obscene materials to adults is open to question. Iowa may have decided that the resources of its prosecutors’ offices should be devoted to matters deemed to have greater priority than the enforcement of obscenity statutes. Such a decision would not mean that Iowa affirmatively desired free distribution of those materials; on the contrary, it would be consistent with a hope or expectation on the State’s part that the Federal Government’s prosecutions under statutes such as § 1461 would be sufficient for the State’s purposes. The State might also view distribution over the counter as different from distribution through the mails. It might conclude that it is easier to keep obscene materials out of the hands of minors and unconsenting adults in retail establishments than it is when a letter or package arrives at a private residence. Furthermore, the history of the Iowa law suggests that the State may have left distribution to consenting adults unregulated simply because it was not then able to arrive at a compromise statute for the regulation of obscenity.
Arguments similar to petitioner’s “nullification” thesis were made in cases that followed Stanley v. Georgia, 394 U. S. 557 (1969). In United States v. 12 200-ft. Reels of Film, 413 U. S. 123 (1973), the question was whether the United States constitutionally might prohibit the importation of obscene material that was intended solely for private, personal use and possession. See 19 U. S. C. § 1305 (a). Stanley had upheld the individual’s right to possess obscene material in the home, and the argument was made that this right would be virtually meaningless if the Government could prevent impor[307] tation of, and hence access to, the obscene material. 413 U. S., at 126-127. The Court held that Stanley had been based on the privacy of the home, and that it represented a considered line of demarcation in the obscenity area. Id., at 127. Consequently, despite the incidental effect that the importation prohibition had on the privacy right to possess obscene material in the home, the Court upheld the statute. A similar result was reached, in the face of similar argument, in United States v. Orito, 413 U. S. 139 (1973). There, 18 U. S. C. § 1462, the statute prohibiting knowing transportation of obscene material in interstate commerce, was at issue. The Court held that Stanley did not create a right to receive, transport, or distribute obscene material, even though it had established the right to possess the material in the privacy of the home. 413 U. S., at 141. See also United States v. Reidel, supra.
In this case, petitioner argues that the Court has recognized the right of States to adopt a laissez-faire attitude toward regulation of pornography, and that a holding that § 1461 permits a federal prosecution will render the States’ right meaningless. See Paris Adult Theatre I v. Slaton, 413 U. S. 49, 64 (1973); United States v. Reidel, 402 U. S., at 357. Just as the individual’s right to possess obscene material in the privacy of his home, however, did not create a correlative right to receive, transport, or distribute the material, the State’s right to abolish all regulation of obscene material does not create a correlative right to force the Federal Government to allow the mails or the channels of interstate or foreign commerce to be used for the purpose of sending obscene material into the permissive State.
Even though the State’s law is not conclusive with regard to the attitudes of the local community on obscenity, nothing we have said is designed to imply that the Iowa statute should not have been introduced into evidence at petitioner’s trial. On the contrary, the local statute on obscenity provides rele[308] vant evidence of the mores of the community whose legislative body enacted the law. It is quite appropriate, therefore, for the jury to be told of the law and to give such weight to the expression of the State’s policy on distribution as the jury feels it deserves. We hold only that the Iowa statute is not conclusive as to the issues of contemporary community standards for appeal to the prurient interest and patent offensiveness. Those are questions for the jury to decide, in its traditional role as factfinder. United States v. Danley, 523 F. 2d 369 (CA9 1975), cert. denied, 424 U. S. 929 (1976).
y
A. We also reject petitioner’s arguments that the prospective jurors should have been asked about their understanding of Iowa’s community standards and Iowa law, and that § 1461 was unconstitutionally vague as applied to him. The particular inquiries requested by petitioner would not have elicited useful information about the jurors’ qualifications to apply contemporary community standards in an objective way. A request for the jurors’ description of their understanding of community standards would have been no more appropriate than a request for a description of the meaning of “reasonableness.” Neither term lends itself to precise definition. This is not to preclude other more specific and less conclusory questions for voir dire. For example, it might be helpful to know how long a juror has been a member of the community, how heavily the juror has been involved in the community, and with what organizations having an interest in the regulation of obscenity the juror has been affiliated. The propriety of a particular question is a decision for the trial court to make in the first instance. In this case,, however, we cannot say that the District Court abused its discretion in refusing to ask the specific questions tendered by petitioner.
B. Neither do we find § 1461 unconstitutionally vague as applied here. Our construction of the statute flows directly [309] from the decisions in Hamling, Miller, Reidel, and Roth. As construed in Hamling, the type of conduct covered by the statute can be ascertained with sufficient ease to avoid due process pitfalls. Similarly, the possibility that different juries might reach different conclusions as to the same material does not render the statute unconstitutional. Roth v. United States, 354 U. S., at 492 n. 30; Miller v. California, 413 U. S., at 26 n. 9. We find no vagueness defect in the statute attributable to the fact that federal policy with regard to distribution of obscene material through the mail was different from Iowa policy with regard to the intrastate sale of like material.
VI
Since the Iowa law on obscenity was introduced into evidence, and the jurors were told that they could consider it as evidence of the community standard, petitioner received everything to which he was entitled. To go further, and to make the state law conclusive on the issues of appeal to prurient interest and patent offensiveness, in a federal prosecution under § 1461, would be inconsistent with our prior cases. We hold that those issues are fact questions for the jury, to be judged in light of the jurors’ understanding of contemporary community standards. We also hold that § 1461 is not unconstitutionally vague as so applied, and that petitioner’s proposed voir dire questions were not improperly refused.
The judgment of the Court of Appeals is affirmed.
It is so ordered.