J IM HANNAH, Justice.
Appellant R.N. appeals the decision of the Craighead County Chancery Court1 denying his petition to establish paternity of a minor child, A.M., who was born to Appellee J.M. during her marriage to Appellee B.M. J.M. and B.M. are still married. In this appeal, we are asked to interpret and harmonize Ark. Code Ann. §§ 9-10-104 (Repl. 1998 and Supp. 2001), 9-10-108 (Repl. 1998 and Supp. 2001), and 16-43-901 (Repl. 1999), which deal with the estabhshment of paternity.
The facts of this case are essentially undisputed. J.M. and B.M. were married in 1992 and are still married. Between late 1996 and early 1997, J.M. and R.N. were involved in an ongoing sexual relationship. During this period of time, J.M. continued to have sexual relations with her husband, B.M. J.M. gave birth to a child, A.M., on August 17, 1997. A.M. has lived with J.M. and B.M. since her birth. While R.N. claims that J.M. told him that “she was 99 percent sure the child was his,” J.M. claims she only said “it was like 95 percent sure” that R.N. was the father of the child. Although R.N. has not established a relationship with A.M., he testified that he wanted to establish a relationship with the child, but that J.M. would not allow him to see her. Since A.M.’s birth, R.N. has seen the child on two occasions, once at J.M.’s home and again at R.N.’s office.
On April 7, 1998, R.N. filed the petition for paternity, and on April 20, 1998, he filed a motion for paternity testing pursuant to Ark. Code Ann. § 9-10-108. J.M. responded denying that R.N. is A.M.’s father and moved to dismiss the action on three grounds: (1) R.N. lacked standing because A.M. is presumed to be legitimate, and the Arkansas paternity statutes only apply to illegitimate children; (2) R.N. has no constitutionally protected interest because he has not established a relationship with A.M.; and (3) R.N. should be equitably estopped from bringing the paternity action because he waited until A.M. was almost nine months old before filing the paternity action.
After a hearing on August 31, 1999, the chancellor granted J.M.’s motion to dismiss R.N.’s petition for paternity. In the order entered on August 15, 2000, the court found that as a matter of law R.N. lacked standing to bring the paternity action and that he is equitably estopped from bringing the action. The trial court also adopted as its conclusions of law the legal arguments in J.M.’s motion to dismiss and brief in support of the amended response to the motion for paternity testing. The pleadings were incorporated by reference in the court’s order.2
I. Standing
In his first point on appeal, R.N. argues that section 9-10-104 of the Arkansas paternity statutes grants him standing and that section 9-10-108 requires the trial court to order paternity or DNA testing upon motion of either party. See Ark. Code Ann. §§ 9-10-104 and 9-10-108. In response, J.M and B.M. contend that R.N. lacks standing under section 9-10-104 because that section grants standing to a putative father only when the child is illegitimate, and A.M. is presumed to be legitimate as she was conceived and born during marriage. J.M. and B.M. further assert that paternity testing should be controlled by Ark. Code Ann. § 16-43-901, which permits the trial judge to order paternity testing if the judge concludes such testing is in the child’s best interest. R.N. responds that section 9-10-104 specifically grants a putative father the right to petition to establish paternity even when the child is presumed legitimate. He states that even though being conceived and born during marriage creates a presumption of legitimacy, that presumption is rebuttable by evidence of impotency, lack of access between husband and wife, or genetic testing. R.N. argues that the use of the phrase “the trial court shall order” in section 9-10-108 makes genetic testing mandatory upon either party’s motion. He relies on our canon of statutory interpretation that a general statute must give way to a specific statute to support his contention that the mandatory language of section 9-10-108 controls because it is specific to a paternity action; whereas, the permissive language in section 16-43-901 is general in that it applies to any court action.
The resolution of the question of R.N.’s standing to petition for paternity requires us to interpret the Arkansas paternity statutes. We review issues of statutory construction de novo because it is our responsibility to determine what a statute means. Clemmons v. Office of Child Support Enforcement, 345 Ark. 330, 47 S.W.3d 227 (2001) (citing Stephens v. Arkansas School for the Blind, 341 Ark. 939, 20 S.W.3d 397 (2000) and Hodges v. Huckahee, 338 Ark. 454, 995 S.W.2d 341 (1999)). While we are not bound by the trial court’s ruling, we will accept the trial court’s interpretation of a statute unless it is shown that the trial court erred. Id. The purpose of statutory interpretation is to give effect to the intent of the General Assembly. Ford v. Keith, 338 Ark. 487, 996 S.W.2d 20 (1999). We first seek the legislature’s intent by giving the words of the statute their ordinary and usual meaning in common language. Stephens v. Arkansas School for the Blind, 341 Ark. 939, 20 S.W.3d 397 (2000). Where the meaning is clear and unambiguous, we do not resort to the rules of statutory interpretation. Id.
R.N. filed his petition to establish his paternity of A.M. under section 9-10-104 of the paternity statutes. This section was amended by Act 1184 of 1995 to read as follows:
9-10-104. Suit to determine paternity of illegitimate child. Petitions for paternity establishment may be filed by:
(1) A biological mother;
(2) A putative father;
(3) A person for whom paternity is not presumed or established by court order; or
(4) The Office of Child Support Enforcement.3
R.N. asserts that section 9-10-104 plainly creates standing for him as a putative father. A “putative father” is defined throughout the Arkansas Code as any man not legally presumed or adjudicated to be the biological father of a child, but who claims or is alleged to be the biological father of the child. See Ark. Code Ann. §§ 9-9-501(11) (Repl. 1998), 9-27-303(42) (Supp. 2001), 16-43-901 (h) (Repl. 1999), 20-18-701(5) (Repl. 2000). R.N. claims to be the biological father of A.M., but he is not legally presumed or adjudicated to be the biological father of A.M. Thus, R.N. is, by statutory definition, a putative father.
As to the phrase, “[s]uit to determine paternity of illegitimate child,” that now appears in section 9-10-104, R.N. contends that it is merely a descriptive heading, and descriptive headings in the code do not have the effect of law. R.N. is correct that descriptive headings in the code are not law. See Ark. Code Ann. § l-2-115(b) (Repl. 1996) (“(b) Unless otherwise provided in this Code, . . . the descriptive headings or catchlines immediately preceding or within the text of the individual sections ... do not constitute part of the law and shall in no manner limit or expand the construction of any section.”). While it is true that a previous version of section 9-10-104, as amended by Act 725 of 1989, did not include the above-quoted descriptive heading, it is now a part of the statute after the General Assembly amended section 9-10-104 in 1995 and included the heading or title of the statute in the enactment of the statute, thus making the heading itself part of the statute. See 1995 Ark. Acts 1184.
Without this phrase, the statute would clearly grant R.N. standing. We must, therefore, determine whether the language in the descriptive heading that is now a part of the statute effectively denies R.N. standing to petition for the establishment of A.M.’s paternity. The paternity statutes do not provide us with a definition of the term “illegitimate child,” but this court has defined that term in Willmon v. Hunter, 297 Ark. 358, 360, 761 S.W.2d 924, 925 (1988): “[A]n illegitimate child is a child who is born at the time that his parents, though alive, are not married to each other.” The paternity statutes at that time provided that “any man alleging to be the father of an illegitimate child may petition . . . for a determination of the paternity of the illegitimate child.” Ark. Code Ann. § 9-10-104(a) (1987).
We also reiterated in Willmon the general principle of law that a child is presumed legitimate if the parents were married at the time of the child’s conception or birth. Id. This principle has been recognized by the General Assembly when enacting laws concerning inheritance. See Ark. Code Ann. § 28-9-209 (1987). In Willmon, we held that the presumption of legitimacy of a child born during a marriage, as well as the presumption of legitimacy of a child conceived but not born during the marriage, are rebuttable and do not preclude a party from litigating the issue of paternity. Willmon v. Hunter, supra. See also, Thomas v. Pacheco, 293 Ark. 564, 740 S.W.2d 123 (1987) (permitting the mother to litigate the issue of illegitimacy even though the child was conceived and born during marriage). In other words, even when the term “illegitimate child” was included within the text of the statute, and not merely in the descriptive heading, we have held that a putative father was not precluded from petitioning to determine paternity in cases where the child was presumed legitimate.
The General Assembly included a reference to the term “illegitimate child” in the 1995 amendments to the paternity statutes knowing of our earlier decisions that a presumption of legitimacy is rebuttable notwithstanding the specific reference to that same term in a previous version of section 9-10-104. See Thomas v. Pacheco, supra., and Willmon v. Hunter, supra. “[W]hen the construction of a statute is at issue, we will presume that the General Assembly, in enacting it, possessed the full knowledge of the constitutional scope of its powers, full knowledge of prior legislation on the same subject, and full knowledge of judicial decisions under preexisting law.” Davis v. Old Dominion Freight Line, Inc., 41 Ark. 751, 756, 20 S.W.3d 326, 329 (2000). Because the legislature is presumed to have known of our decisions, we conclude that the plain language of section 9-10-104 grants R.N. standing to petition to determine the paternity of A.M. In other words, it gives R.N. the opportunity to bring his cause before the court.
Although section 9-10-104 gives R.N. standing to petition for paternity, at issue here is whether paternity testing is mandatory under section 9-10-108 or discretionary under section 16-43-901 in relation to these facts. R.N. urges this court to hold that the trial court erred in refusing to order the DNA testing as requested in his motion for paternity testing pursuant to Ark. Code Ann. § 9-10-108. The trial court applied section 16-43-901, which is permissive and allows a trial court to determine what is in the child’s best interest before ordering a paternity test. See Ark. Code Ann. § 16-43-901 (g). R.N. argues that the mandatory testing required under section 9-10-108 should control because it is a specific statutory right to DNA testing in the course of a paternity proceeding, and. the best interest analysis should be done after the trial court has the benefit of all the material facts, including the DNA or paternity test.
Whether sections 9-10-108 and 16-43-901 conflict is a question of statutory interpretation. We have often noted that “[i]t has long been the law in Arkansas that a general statute must yield when there is a specific statute involving the particular subject matter.” Shelton v. Fiser, 340 Ark. 89, 94, 8 S.W.3d 552, 560 (2000). See also, Board of Trustees v. Stodola, 328 Ark. 194, 942 S.W.2d 255 (1997); Donoho v. Donoho, 318 Ark. 637, 887 S.W.2d 290 (1994); Conway Corp. v. Construction Eng’rs, Inc., 300 Ark. 225, 782 S.W.2d 36 (1989). However, statutes relating to the same subject are said to be in pari materia and should be read in a harmonious manner, if possible. Stephens, supra; Minnesota Mining & Mfg. v. Baker, 337 Ark. 94, 989 S.W.2d 151 (1999).
While the language of the two statutes appears at first to be in conflict, a full reading of the statutes and the situations to which they apply clarify that section 16-43-901 is the more specific of the two and can be applied harmoniously with section 9-10-108. Under section 9-10-108, the trial court is directed that it “shall” order testing upon the motion of either party to the paternity action; whereas, under section 16-43-901 the trial court “may” order testing where it can assist the trial judge in the determination of paternity in the particular situation where the child is presumed legitimate by being bom during the marriage of the mother and her husband. Section 16-43-901 (g) instructs the trial court to consider the best interest of the child in determining paternity in the specific situation when the child is presumed legitimate; whereas, section 9-10-108 contains no such instruction for the general determination of paternity. By finding that section 16-43-901 addresses a more limited and specific situation than does section 9-10-108, we not only can address the particular situation of determining the true parentage of a presumed legitimate child born of a marriage, but the court can also harmonize these two statutory sections.
As the court of appeals noted in Leach v. Leach, 57 Ark. App. 155, 942 S.W.2d 286 (1997), Act 657 of 1989, codified at section 16-43-901, abolished Lord Mansfield’s Rule. The court of appeals stated:
The common-law rule, articulated in 1777, states the declarations of husband and wife cannot be admitted to bastardize a child born after marriage. The statute now permits a mother, her husband, and a putative father to testify about the paternity of a child. However, the strong presumption of the legitimacy of a child born of marriage continues to be one of the most powerful presumptions in Arkansas law. Only upon clear and convincing evidence may the court find this presumption overcome. This statute also provides:
The court shall consider foremost the interest of the child in making any determination hereunder and consider only testimony and evidence which will serve the best interest of the child in its findings pursuant to this section.
Id. at subsection (g)(2).
In Leach, the court of appeals reversed the chancellor’s decision to award custody of two children born of the marriage, although the older child was admittedly not the husband’s, to the mother so that the children would not be separated, although the father had had temporary custody during the divorce proceedings. While the issue of paternity testing did not arise in that case because the husband and wife did not make it an issue, the issue of paternity itself was raised sua sponte by the court. The chancellor determined that because the older child was not the husband’s, the husband could not have custody of her. The court of appeals reversed because illegitimizing the daughter was not in her best interest under the facts of that particular case. The court of appeals recognized that in considering paternity involving a child born of a marriage whose legitimacy is presumed, such a special and specific situation arises requiring the chancellor to step in and exercise discretion to determine an outcome in the best interest of the child whose fife will be most affected by any change in parentage. See Ark. Code Ann. § 16-43-901(g)(l) and (2). While Leach has no precedential value for us, its reasoning is sound and in accordance with the application of this statute to this specific situation. The discretionary “may” language in section 16-43-901(e)(1) allows a chancellor to consider the particular circumstances of each case and the child’s best interest before ordering a paternity test that could forever change a child’s life, perhaps merely because the adults who caused such a tumultuous situation are curious to know the results of their infidelity.
Furthermore, because the bulk of section 16-43-901 addresses such a specific situation rather than the general situation of establishing paternity under section 9-10-108, R.N.’s contention that section 9-10-108 is more specific merely because it uses the word “shall” is in error. By reaching that conclusion, we would necessarily void the language in section 16-43-901(e)(1), which gives the trial judge discretion to order the test if it assists the court in the determination of parentage after considering the child’s best interest under section 16-43-901(g) (2). Instead, by our determination that section 16-43-901 is more specific in its application to this particular type of paternity challenge than the general paternity-testing statute at section 9-10-108, both statutes can be read in harmony to recognize that the presumption of legitimacy of a child born during a marriage is a presumption to protect the child whose interests should be considered first and foremost. And while this presumption is rebuttable according to law, the challenging party must first show that rebutting that presumption is in the best interest of a child whose parents were married at the time the child was born and perhaps, as in this case, remain married and plan to continue as the only parents the child has ever known.
Opponents to our decision would argue that giving the trial judge discretion in such a case would erase a putative father’s ability to rebut the presumption of legitimacy where perhaps the only way to rebut that presumption is through DNA testing. However, it is this discretion in section 16-43-901 that allows the trial judge to provide the necessary level of objective reasoning to protect the best interest of a child who is presumed legitimate while still considering the interests of a putative father or other party who seeks to rebut the presumption. Otherwise, the presumption of legitimacy loses any real meaning if a putative father, for instance, has the ability, by merely requesting a paternity test, to forever change the presumed legitimacy of a child born of a marriage. We are not willing to minimize this presumption where section 16-43-901 clearly addresses a specific situation in which paternity is challenged within the larger and less specific arena of paternity challenges under section 9-10-108.
In two particular cases in the 1980s, we addressed the issue of a party’s ability to challenge paternity when a child is presumed legitimate. In Thomas v. Pacheco, supra, we allowed a mother to litigate the issue of paternity even though the child was conceived and born during her marriage. We noted that while there is a strong presumption of legitimacy for a child born during marriage, the presumption was rebuttable by evidence of the father’s impotence or the non-access of the parties. Id. We reversed the trial court’s findings concerning paternity for two reasons. One, the trial court erred in allowing the husband and wife to testify concerning non-access during the period of conception. Lord Mansfield’s Rule, a rule of evidence dating back to the 1770s and adopted in Arkansas in 1915, prohibited a husband or wife from testifying concerning non-access of the husband. Thus, the trial judge abused his discretion in allowing the testimony. Id. Second, we held that even though blood tests established a 99.5% probability that the husband was not the father, the court failed to follow the required procedure by allowing a telephone deposition, rather than a personal appearance, by the doctor who performed the test. Id. Significantly, we did not dismiss the case but remanded it, allowing the parties to continue to litigate the issue of paternity in spite of the presumption of legitimacy and the wording of the statute that appeared to limit petitions to cases of an illegitimate child. Id.
In Willmon v. Hunter, supra, we upheld the right of a putative father to litigate the issue of paternity over the presumption of legitimacy of a child conceived during marriage but born out of wedlock. In deciding that case, we held that the presumption of legitimacy was not irrebuttable. We also held that there was no public policy that would prohibit a putative father from seeking to establish his paternity of a child presumed legitimate. Id. In 1988, we held that a putative father was not entitled to notice because he did not avail himself of his rights to petition for paternity or take other affirmative action to establish a relationship with the child. In re the Adoption of S.J.B., 294, Ark. 598, 745 S.W.2d 606 (1988). Furthermore, we stated: “The Arkansas law governing the establishment of paternity by the county court is applicable to all putative fathers.” Id. at 603. The Willmon holding, like the Pacheco and Adoption of S.J.B. holdings, were made under the 1981 statute, the text of which specifically referred to an illegitimate child.
While these cases establish that a putative father or other recognized party under section 9-10-104 may petition to establish paternity, a matter we do not dispute here, any further application of those decisions to this case must fail. Those cases were decided prior to the enactment of section 16-43-901 through Act 657 of 1989, which generally did away with Lord Mansfield’s Rule. Thus, while Thomas v. Pacheco and Willmon v. Hunter recognize a party’s standing to challenge presumed paternity, the language in section 16-43-901 still retains the trial judge’s discretion to consider first and foremost the best interest of the child before making any decision regarding the receipt of evidence, including whether to order DNA tests. See Ark. Code Ann. § 16-43-901(e)(l) and (g)(2).
In conclusion on this issue, we find that the trial court erred in holding that R.N. did not have standing to petition to establish paternity. We reverse and remand to the circuit judge with the instruction that prior to ordering paternity testing, the circuit judge shall first conduct a hearing to determine whether it is in the best interest of the child to order a paternity test pursuant to section 16-43-901(g) (2), and then to further determine any related issues pursuant to the directives of that statute.
II. Equitable Estoppel
Even though R.N. has statutory standing, J.M. and B.M. assert that R.N. should be equitably estopped from bringing a paternity action because he waited until A.M. was almost nine months old before initiating the action. R.N. argues that J.M. and B.M. failed to present sufficient facts to meet their burden of proof on the elements of equitable estoppel. The trial court ruled that as a matter of law, R.N. was estopped from pursuing his paternity action. We review chancery cases de novo on the record, but we will not reverse a chancellor’s findings of fact unless they are clearly erroneous. Wisener v. Burns, 345 Ark. 84, 44 S.W.3d 289 (2001).
We have defined equitable estoppel as “a judicial remedy by which a party may be precluded by its own act or omission from asserting a right to which it otherwise would have been entitled, or pleading or proving an otherwise important fact.” Clemmons, 345 Ark. at 352 (citing 28 Am. JUR.2d Estoppel and Waiver, Page 353 § 28 (2000)). We have established four necessary elements of equitable estoppel:
(1) the party to be estopped must know the facts; (2) the party to be estopped must intend that his or her conduct be acted on or must so act that the party asserting the estoppel had a right to believe it was so intended; (3) the latter must be ignorant of the true facts; and (4) must rely on the former’s conduct to his or her injury.
Miller County v. Opportunities, Inc., 334 Ark. 88, 96, 971 S.W.2d 781 (1998). The essence of J.M. and B.M.’s estoppel argument is that R.N. should be estopped from bringing a paternity action because, although he knew that he was probably A.M.’s biological father, he allowed B.M. to establish and develop a close relationship with A.M. during the first nine months of the child’s life.
B.M., as the proper party to assert the equitable estoppel claim, had the burden of proving each of the four elements of equitable estoppel. However, there is no proof in the record as to what B.M. knew and when, although at some point he knew there was a question about A.M.’s paternity. Furthermore, B.M. offered no evidence to show that he relied on R.N.’s conduct to his detriment. We must therefore conclude that, without the strict proof necessary to support B.M.’s estoppel claim, the trial court was clearly erroneous in concluding that R.N. was equitably estopped from bringing the paternity action as a matter of law.
III. Equal Protection
The dissent asserts that by reaching this conclusion we are violating the Equal Protection Clause of the Fourteenth Amendment of the United States Constitution because we are “discriminating” against illegitimate children by not providing them a “best interest” hearing upon the determination of paternity. Nothing could be further from the truth.
To begin with, we note that none of the parties to this action raised this issue in the trial court, and they do not attempt to raise the issue in their briefs to this court. The dissent raises this issue sua sponte despite our longstanding rule that, with the notable exception of matters involving subject-matter jurisdiction, we will not consider issues raised for the first time on appeal, even where the issue is a matter of constitutional magnitude. Furman v. Holloway, 312 Ark. 378, 383, 849 S.W.2d 520, 523 (1993); Burke v. Strange, 335 Ark. 328, 983 S.W.2d 389 (1998), Tabor v. State, 333 Ark. 429, 971 S.W.2d 227 (1998).
On the merits, the dissent bases its argument on Gomez v. Perez, 409 U.S. 535 (1973), a case in which the United States Supreme Court determined that a Texas court’s action in a paternity and support case violated the Equal Protection Clause. In Gomez, the appellant filed a petition in Texas District Court seeking support from the appellee on behalf of her minor child. After a hearing, the state trial judge found that appellee was “the biological father” of the child, and that the child “needs the support and maintenance of her father,” but concluded that because the child was illegitimate “there is no legal obligation to support the child and the Plaintiff take nothing.” The Court of Civil Appeals affirmed this ruling over the objection that this illegitimate child was being denied equal protection of law. The Texas Supreme Court refused application for a writ of error, finding no reversible error. On review, the Supreme Court held that a state may not “invidiously discriminate” against illegitimate children by denying them substantial benefits accorded children generally, and that once a state creates a judicially enforceable right on behalf of children for necessary support from their natural fathers, there is no constitutionally sufficient justification for denying these necessary rights to a child simply because her natural father has not married her mother, and such denial is a denial of equal protection.
Clearly, the Court in Gomez saw that providing fewer rights to a child simply because he or she is illegitimate is a violation of equal protection. The Gomez case and its holding neither factually nor substantively apply here, however. Rather, in this case, by requiring paternity testing under Ark. Code Ann. § 9-10-108 in a case involving an illegitimate child, the courts will actually be effectuating the intent of the United States Supreme Court in Gomez by requiring that illegitimate children who do not have a father wifi not only be able to establish parentage, but will also be afforded all of the rights and benefits accorded children who are presumed legitimate. Hence, the “best interest” of an illegitimate child, including but not limited to the rights and benefits of having a father and the right of receiving support from the father, will always be to have parentage established for an illegitimate child, thus negating any need for a “best interest” hearing under Ark. Code Ann. § 16-43-901. The State, as well, will benefit from the establishment of paternity for an illegitimate child where certain support obligations will transfer to the rightful bearer of those responsibilities. Furthermore, required testing under Ark. Code Ann. § 9-10-108 in a case involving an illegitimate child actually raises the rights of an illegitimate child to the same level as those who are presumed legitimate, thus satisfying the Equal Protection Clause by actually conferring upon them “substantial benefits accorded to children generally.” Gomez, 409 U.S. at 538 (1973).
As a final point, R.N. argues that the trial court erred in ruling that he did not have a protectable constitutional interest that would grant him standing. Because we have ruled that R.N. has statutory standing to bring the petition, we need not address this point.
Reversed and remanded.
Thornton, J., concurs. Glaze, Brown, and Imber, JJ., dissent.