OPINION

By the Court, PICKERING, J.:

Delbert Roy Douglas fathered two children with his daughter, whom he forced to have sex with him when she was 12 and, again, after she turned 18. He was charged with and convicted of sexual assault and incest for both rapes. On appeal, Douglas challenges his incest convictions. He argues that incest requires mutual consent while sexual assault is, by definition, nonconsensual, making the two crimes mutually exclusive. We hold, as the majority of courts have held, that incest condemns sex between close relatives without regard to whether the intercourse was consensual.

I.

A.

Our review is de novo, State v. Lucero, 127 Nev. ___, ___, 249 P.3d 1226, 1228 (2011), and begins with the text of Nevada's incest statute:

NRS 201.180.

Obviously, NRS 201.180 omits any express mutual consent requirement. But Douglas parses the statute as punishing "[p]ersons being within the degree of consanguinity within which marriages are declared by law to be incestuous and void ... who commit fornication ... with each other" and infers a mutual consent requirement from its key terms: persons, commit, fornication, and with each other. "Unlike sexual assault," Douglas argues, "incest is not a crime perpetrated by one person against another; it is the joint operation of two or more prohibited persons who, together, `commit fornication.'" And "fornication," Douglas continues, means "`consensual sexual intercourse between two persons not married to each other.'" Id. at 8 & n. 2 (quoting Merriam-Webster's Online Dictionary, http://www.merriam-webster. com/dictionary/fornication (last visited, July 20, 2012)).

Nevada's prohibition on incest dates back to 1861. 1861 Laws of the Territory of Nevada, ch. 28, § 129, at 83. Though the penalty has changed over time, see 1979 Nev. Stat., ch. 655, § 43, at 1429; 1995 Nev. Stat., ch. 443, § 83, at 1198; 2005 Nev. Stat., ch. 507, § 31, at 2877, the words used to describe incest's elements have not varied.1 In general, "[w]ords must be given the meaning they had when the text was adopted." Antonin Scalia & Bryan A. Garner, Reading Law: The Interpretation of Legal Texts 78 (2012). So, we look to references from the late 19th century to glean the meaning of NRS 201.180.

To Douglas, the phrase "with each other" unambiguously requires mutual consent. But 19th century scholarly references primarily defined with as in the "presence" or "company of." Rev. James Stormonth, Dictionary of the English Language 733 (1877); see also William Dwight Whitney, The Century Dictionary 6952 (1895) (defining with as "in company with"). Thus, "with each other" requires only that the charged party commit the act of incest in the company of the person with whom he or she intermarries or fornicates. The phrase is indeed unambiguous,2 but it does not demand the consent of both parties to support a conviction.

Douglas also argues that the phrase "persons ... who commit" requires mutual consent. We disagree. Commit is defined as "to do or effect," Stormonth, supra, at 99, or "to perpetrate." Whitney, supra, at 1131. Thus, the phrase "persons ... who commit" sanctions punishment for those persons who voluntarily carry the incestuous act into execution, and prevents the prosecution of those who do not. This requirement shields rape victims and certain minors from prosecution for incest, but it does not demand mutual consent.

Nor do we agree that fornication signifies consensual sexual intercourse. Stormonth defines fornication as sexual intercourse "between unmarried persons." Stormonth, supra, at 215. Whitney similarly defines it as "illicit sexual intercourse on the part of an unmarried person with a person of the opposite sex, whether married or unmarried." Whitney, supra, at 2340. These early definitions focus on marital status of the participants, not consent.

Though helpful, historical dictionaries are not "perfect repositories." Note, Looking It Up: Dictionaries and Statutory Interpretation, 107 Harv. L.Rev. 1437, 1445, 1447 (1994). Douglas supports his reading of NRS 201.180 with Merriam-Webster's Online Dictionary, supra, which defines fornication as "consensual sexual intercourse." But other modern dictionaries do not include "consensual" in their definitions of fornication. See, e.g., Webster's Seventh New Collegiate Dictionary 329 (1969). And Douglas's reference to the online dictionary provides no prefatory material, or information as to editor, year of publication, or depth, making it impossible to weigh his definition's relative credibility.

A more reliable modern resource is Black's Law Dictionary. See Rugamas v. Eighth Judicial Dist. Court, 129 Nev. ___, ___, 305 P.3d 887, 893 (2013). The definition of fornication offered by Black's is "voluntary sexual intercourse with an unmarried woman" or "[v]oluntary sexual intercourse between two unmarried persons." Black's Law Dictionary 679 (8th ed.2009). These definitions mirror those provided by Stormonth and Whitney, except for Black's inclusion of the word voluntary. See Stormonth, supra, at 215; Whitney, supra, at 2340.

One definition of voluntary is "not impelled." Black's Law Dictionary 1605 (8th ed.2009). Under that definition, fornication suggests mutual consent. But voluntary may also mean "by ... intention." Id. Under this definition, a conviction for incestuous fornication requires an intentional act by the accused, like all crimes in Nevada. NRS 193.190 ("In every crime or public offense there must exist a union, or joint operation of act and intention...."). But it would not demand mutual consent.

B.

The majority of courts that have considered statutes like NRS 201.180 have refused to infer a mutual consent requirement. Most states passed statutes criminalizing incest by the late 1800s. Joel Prentiss Bishop, Commentaries on the Law of Statutory Crimes § 728, at 442 (2d ed.1883). Although "[t]hese statutes [were] not precisely the same in all states," they were "substantially so." William Lawrence Clark & William Lawrence Marshall, A Treatise on the Law of Crimes § 460, at 704 (2d ed.1905). For the most part, these statutes were worded like NRS 201.180: They "punish[ed] any persons who, being within the degrees of consanguinity... within which marriages are declared to be incestuous and void, intermarry or commit adultery or fornication with each other." Id. By 1905, "in most states," it was the settled law that "the consent of both parties is not a necessary element of the offense" of incest. Id. at 705; Recent Case, Incest — Elements of Offense — Relation, of Parties, 22 Yale L.J. 625 (1913) ("According to the weight of authority assent of both parties is not necessary to constitute the crime of incest."); L.S. Tellier, Annotation, Consent as element of incest, 36 A.L.R.2d 1299 (1954) ("While [incest] statutes generally forbid persons within specified degrees of consanguinity or affinity to have sexual intercourse `with each other' or `together,' in most jurisdictions the courts do not regard the words `with each other' or `together,' as requiring a mutual consent to the wrongful act in order that incest may be committed, the purpose of the statutes being to deter the commission of fornication or adultery with one within the prohibited degrees of relationship, and to punish the accused regardless of whether or not the other party consented to the act or whether or not force was used to overcome the other's resistance.").

Nevada appears to have copied its incest statute from California. Compare 1861 Laws of the Territory of Nevada, ch. 28, § 129, at 83, reprinted supra note 1, with 1850 Cal. Stat. 244 ("Persons being within the degrees of consanguinity, within which marriages are declared by law to be incestuous and void, who shall intermarry with each other, or who shall commit fornication or adultery with each other, shall, on conviction, be punished by imprisonment in the State Prison... ."); see also 5 Nev. Compiled Laws § 10140 (1929) (citing Cal.Penal Code § 285, where 1850 Cal. Stat. 244 was eventually codified, as a resource for Nevada's incest statute). In People v. Stratton, 141 Cal. 604, 75 P. 166, 167 (1904), superseded by statute on other grounds as stated in People v. Tobias, 25 Cal.4th 327, 106 Cal.Rptr.2d 80, 21 P.3d 758, 766 (2001), the California Supreme Court considered and rejected the text-based mutual-consent arguments Douglas reprises here. In its view, such "reasoning does not commend itself because it makes "mutuality of agreement and joint consent ... the essence of the crime" in an improper judicial revision of the "express declaration of the [statutory] law." Id. Adding a mutual consent requirement to the statute disserves its purpose:

Id., quoted with approval in State v. Hittson, 57 N.M. 100, 254 P.2d 1063, 1065 (1953); see also Tellier, supra, 57 N.M. 100, 254 P.2d 1063, 36 A.L.R.2d at 1296 (reproducing Hittson as the lead case for the annotation).

Douglas suggests that the wording of Nevada's incest statute is unique and distinguishes the cases holding incest does not require mutual consent. But this is not accurate. Early cases abound, construing incest statutes indistinguishable from Nevada's and rejecting the idea that incest requires mutual consent.

In People v. Barnes, 2 Idaho 148, 9 P. 532 (1886), for example, the Supreme Court of the Territory of Idaho considered Idaho's incest statute — a statute identical to Nevada's. Compare id. at 532 (reprinting 1875 Eevised Laws of the Territory of Idaho, ch. 10, § 129, at 353), with 1861 Laws of the Territory of Nevada, ch. 28, § 129, at 83, reprinted supra note 1. In Barnes, the defendant tendered the same arguments about "fornication" and "with each other" requiring mutual consent that Douglas does. Barnes, 9 P. at 534. Quoting contemporary authorities, the Idaho Territorial Court noted that one defines "fornication" as "`the unlawful knowledge by an unmarried person of another,'" which "does not imply that carnal knowledge must necessarily be mutual," while the other "defines it to be `the voluntary sexual intercourse of one person with another.'" Id. These definitions establish that the defendant must act volitionally but not that the intercourse must occur consensually. As the Barnes court rhetorically asks: "There must be a voluntary consent of the will on the part of the one, but may not the other party to the act be the victim of force or fraud, or a child so young that the law regards her incapable of giving consent?" Id. The Barnes court's conclusion that incest does not require mutual consent was not simply policy-based but text-based as well:

Id. at 534-35 (emphasis added).

Addressing statutes with the same wording as NRS 201.180 and coming to the same conclusion as Stratton and Barnes are: McCaskill v. State, 55 Fla. 117, 45 So. 843, 844-45 (1908) ("The fact that the defendant, who had carnal intercourse with his daughter, used some force to overcome the resistance actually made by her, does not render the act the less incestuous."); David v. People, 204 Ill. 479, 68 N.E. 540, 542 (1903) ("the consent of the female is not necessary to constitute the crime of incest by the male"); Keeton v. State, 549 So.2d 960, 961 (Miss. 1989) ("If this Court has not before adopted, we here adopt the majority position that consent is not a necessary element of incest."); Hittson, 254 P.2d at 1065 ("[T]he purpose of the [incest] statute is to prevent sexual intercourse between close relatives, and the free act of the one being tried, with knowledge of the relationship, is all that is required. It is immaterial that the same testimony would have sustained a conviction for rape."); Signs v. State, 35 Okla.Crim. 340, 250 P. 938, 940 (Okla.Crim.App.1926) ("incest is proved, although the female was incapable of and did not give her consent or voluntarily participate in the act of intercourse"); State v. Nugent, 20 Wn. 522, 56 P. 25, 26 (1899) ("If it be true that both parties must be guilty or neither can be, then it must follow that if the female is under the age of consent, or an imbecile, the crime cannot be incest. We cannot subscribe to such a doctrine. It is illogical, and in disregard of the fundamental principle that each must answer for the consequences of his own act, and his own guilt does not depend upon the conduct or mental condition of another.").

DeGroat v. People, 39 Mich. 124 (1878), on which Douglas relies, and State v. Jarvis, 20 Or. 437, 26 P. 302 (1891), are the exceptions to the rule established by the cases just cited. They address statutes similar to NRS 201.180 and deem mutual consent an element of incest. But no court outside Michigan or Oregon has cited either decision approvingly since the end of the 19th century, while many have considered and rejected their holdings. See Stratton, 75 P. at 167 (DeGroat and Jarvis are products of "judicial construction" not proper statutory interpretation); David, 68 N.E. at 542-43 (rejecting DeGroat and Jarvis); State v. Freddy, 117 La. 121, 41 So. 436, 437-38 (1906) (construing a differently worded statute but rejecting the rule in DeGroat and Jarvis; "the aim of the [incest] statute is to prevent the unnatural sexual intercourse, and this intercourse exists none the less if accomplished against the will of one of the parties, and the act is none the less incest because it happens also to be rape"); Hittson, 254 P.2d at 1064-65 (rejecting DeGroat and Jarvis); Signs, 250 P. at 940 (citing DeGroat and Jarvis as exceptions to the better-reasoned general rule); State v, Winslow, 30 Utah. 403, 85 P. 433, 435 (1906) (construing a differently worded statute but rejecting DeGroat and Jarvis; "the great weight of authority is to the effect that when the incestuous fornication is shown to have been committed by the defendant with full knowledge of the relationship between himself and the other participant, though he used force in the accomplishment of his object, he may, nevertheless, be convicted of the crime of incest"); Nugent, 56 P. at 26 (rejecting DeGroat and Jarvis as "illogical").

Two courts that started down the DeGroat and Jarvis path, State v. Thomas, 53 Iowa 214, 4 N.W. 908, 910 (1880); Noble v. State, 22 Ohio St. 541, 545 (1872), considered statutes worded differently from NRS 201.180, and, more to the point, did not stay the course. Thomas was a 3-2 decision from which, to the extent it supported the mutual consent rule contended for here, the Iowa Supreme Court soon retreated. See State v. Hurd, 101 Iowa 391, 70 N.W. 613, 615 (1897) ("`A person may be convicted of incest though he accomplish his purpose by such force as to render him also guilty of rape.'" (quoting headnote 1 to Smith v. State, 108 Ala. 1, 19 So. 306, 306 (1896))); see also State v. Chambers, 87 Iowa 1, 53 N.W. 1090, 1092 (1893) ("Guilt may exist and is none the less enormous, because the act was without the consent of the female. To hold otherwise is to say that the crime of incest cannot be committed with one who, from infancy or other cause, is incapable of consenting to the act."). And Noble's passing reference to incest being "committed by two willing parties," 22 Ohio St. at 545, was later dismissed as dictum in State v. Robinson, 83 Ohio St. 136, 93 N.E. 623, 624 (1910) ("The question whether consent is an essential ingredient of the crime [of incest] was not presented in the case of Noble v. State."). See also id. ("[I]n the great majority of states it is held that the consent of both parties is not essential, and that a defendant may be convicted of incest though he use such force as makes it rape. We think the better reason is with the majority.").3

C

"It would seem a strange rule of law, that a man indicted for incest might escape conviction and secure an acquittal, by satisfying the jury that he overcame the woman by force and violence." Straub v. State, 27 Ohio C.C. 50, 55 (Ohio Cir.1904). Yet, this is the rule Douglas champions and DeGroat and Jarvis endorse. Such a rule is supported neither by the text of NRS 201.180 nor the majority of cases to have interpreted comparable texts. And adopting the rule in DeGroat and Jarvis would thwart the evident purpose of the prohibition against incest — protecting families and the welfare of children, and preventing genetic mutations. Leigh B. Bienen, Defining Incest, 92 Nw. U.L.Rev. 1501, 1536 (1998) ("The goals incorporated within traditional incest statutes include: the orderly regulation of marriage, the prevention of biologically harmful inbreeding ... and the setting out of punishment for sexual behavior perceived as deviant or exploitative."). Most incest convictions involve sexual, contact between an adult and a minor whose legal and psychological capacity to consent is, at best, debatable. See People v. Facey, 115 A.D.2d 11, 499 N.Y.S.2d 517, 520 (1986). Making consent an element of incest leaves NRS 201.180 unusable in the context in which its application seems most apt.

"A textually permissible interpretation that furthers rather than obstructs the document's purpose should be favored." Scalia & Garner, supra, at 63. If the Legislature wanted to make mutual consent an element of incest, it would have been easy to do but it did not; courts should not add things to what a statutory text states or reasonably implies. Id. at 93. Absent clear textual instruction otherwise, we decline to presume that a legislature acting in this environment would sanction lack of consent as a defense to incest, particularly when the defense would primarily serve those accused of assaulting the children whose accessibility, due to family ties, is greatest. See Facey, 499 N.Y.S.2d at 520.

D.

The rule of lenity requires that we liberally interpret an ambiguous criminal law in favor of the accused. Lucero, 127 Nev. at ___, 249 P.3d at 1230. But the principle applies only after this court has used every interpretive tool at its disposal and "a reasonable doubt persists." Moskal v. United States, 498 U.S. 103, 108, 111 S.Ct. 461, 112 L.Ed.2d 449 (1990). And given the analysis above, this court is not left with reasonable doubt as to the meaning of NRS 201.180.

II.

Our reading of NRS 201.180 disables Douglas's remaining arguments. While the jury instructions — to which Douglas did not properly object — did not make mutual consent an element of incest or define "fornication" in terms of "consent," this was not error, plain or otherwise, since the crime of incest does not require mutual consent. See Green v. State, 119 Nev. 542, 545, 80 P.3d 93, 95 (2003).

Douglas's double jeopardy challenge also fails. Sexual assault and incest each "contains an element not contained in the other." Jackson v. State, 128 Nev. ___, ___, 291 P.3d 1274, 1278 (2012). Incest requires familial relationship, NRS 201.180, while sexual assault does not. NRS 200.366. And sexual assault makes nonconsent of the other party a clear condition for conviction, NRS 200.366(1), while incest does not. Also, the text of neither statute suggests that a conviction under one precludes a conviction under the other. Thus, Douglas's convictions for both incest and sexual assault did not violate double jeopardy.

We affirm.

We concur: GIBBONS, C.J., and HARDESTY, PARRAGUIRRE, DOUGLAS, CHERRY and SAITTA, JJ.