(dissenting, with whom Lynch, J., joins). The issue presented by this case is whether the plaintiff has standing to invoke the jurisdiction of the Probate Court to inquire into and decide whether he is the father of a child born to a woman who (1) was married to another man when *692the child was conceived and born, and (2) now lives with that husband, who accepts the child as his own. Stated another way, the issue is whether, in those circumstances, the husband is conclusively presumed to be the father. If he is, evidence to the contrary is legally irrelevant. See Michael H. v. Gerald D., 109 S. Ct. 2333, 2340 (1989).
The court’s abundant discussion of the evidentiary rebuttable presumption of legitimacy, the court’s expressed abandonment of that evidentiary principle, and its substitution of a rule “requiring that a putative father in the plaintiffs position be required to prove paternity by clear and convincing evidence” have no bearing on the issue before the court. Consideration of the adequacy of evidence and the proper standard by which a plaintiffs paternity is proven assumes that the answer to the issue before the court is that, in the circumstances of this case, the husband is not deemed the father as a matter of law and the putative father has standing to litigate the paternity issue. Because the court’s discussion assumes the answer to the issue, the discussion does not contribute to its resolution.
Not until the fourth quarter of its opinion does the court address the issue. There it announces its decision that a man in the plaintiffs position has a right, not as a matter of constitutional guarantee but as a matter of policy, to be heard on the question of paternity. Ante at 689. Reasoning that “[t]he existence of a substantial parent-child relationship is ... the controlling factor in determining whether this plaintiff may pursue his claim,” the court concludes that, “[o]n this record, there is sufficient evidence of a substantial parent-child relationship between the plaintiff and the child to allow the plaintiff to proceed with his paternity action.” Ante at 689.
The existence of a substantial parent-child relationship is important to a determination whether a putative father of a child born out of wedlock has a due process right to assert his fatherhood. In cases involving a man’s claim that he is the father of a child born to an unmarried mother, the United States Supreme Court has said: “When an unwed fa*693ther demonstrates a full commitment to the responsibilities of parenthood by ‘com[ing] forward to participate in the rearing of his child,’ . . . his' interest in personal contact with his child acquires substantial protection under the Due Process Clause.” Lehr v. Robertson, 463 U.S. 248, 261 (1983), quoting Caban v. Mohammed, 441 U.S. 380, 391 (1979). See Quilloin v. Walcott, 434 U.S. 246 (1978); Stanley v. Illinois, 405 U.S. 645 (1972). The fact, however, that a substantial parent-child relationship is important in assessing the constitutional right of a putative father in the child-born-out-of-wedlock context suggests nothing with respect to whether, as a matter of constitutional analysis or mere policy, such a relationship ought to be recognized as bearing in any significant way on the question whether the putative father may assert that he is the father of a child born in wedlock. There is an immense difference between the two situations. Justice Scalia, in Michael H. v. Gerald D., supra, a case remarkably similar to the case at bar, explains why this is so.
The plaintiff’s argument in Michael H. was “predicated on the assertion that [he had] a constitutionally protected liberty interest in his relationship with [the child].” Id. at 2341. Justice Scalia, writing for a plurality consisting of the Chief Justice, Justice O’Connor, Justice Kennedy, and himself, noted that the term “liberty” in the due process clause extends beyond freedom from physical restraint to interests that are “so rooted in the traditions and conscience of our people as to be ranked as fundamental.” Id., quoting Snyder v. Massachusetts, 291 U.S 97, 105 (1934). The plaintiff in Michael H. had argued that Lehr v. Robertson, supra, Caban v. Mohammed, supra, Quilloin v. Walcott, supra, and Stanley v. Illinois, supra, established that a liberty interest for due process clause purposes was “created by biological fatherhood plus an established parental relationship.” Id. at 2342. In response to the plaintiff’s argument, Justice Scalia wrote: “We think that distorts the rationale of those cases. As we view them, they rest not upon such isolated factors but upon the historic respect — indeed, sanctity would not be too strong a term — traditionally accorded to the relationships *694that develop within the unitary family.” Id. at 2342. In a footnote, Justice Scalia explains: “The family unit accorded traditional respect in our society, which we have referred to as the ‘unitary family,’ is typified, of course, by the marital family, but also includes the household of unmarried parents and their children. Perhaps the concept can be expanded even beyond this, but it will bear no resemblance to traditionally respected relationships — and will thus cease to have any constitutional significance — if it is stretched so far as to include the relationship established between a married woman, her lover and their child . . . .” Id. at 2342 n.3.
The legal issue in Michael H. v. Gerald D., supra, then, according to Justice Scalia, was whether the relationship between the plaintiff stranger to the mother’s marriage and the child “has been treated as a protected family unit under the historic practices of our society, or whether on any other basis it has been accorded special protection.” Id. at 2342. He wrote: “We think it impossible to find that it has. In fact, quite to the contrary, our traditions have protected the marital family . . . against the sort of claim Michael asserts” (footnote omitted). Id.
Because the “unitary family” accorded traditional respect may include the putative father, mother, and child born out of wedlock, but does not include the mother, child born in wedlock, and the mother’s lover, the substantial parent-child relationship test applicable in the former context has no relevancy to the latter either as a matter of constitutional analysis or for policy formation purposes.
The holding in Michael H. v. Gerald D., supra, makes clear that the plaintiff herein does not have a constitutionally protected interest in obtaining an adjudication that he is the father of the child. The court here does not contend that he does, but instead declares that, as a matter of judicially declared policy (common law), the plaintiff is entitled to an adjudication of paternity if he demonstrates a substantial parent-child relationship between himself and the child. In my view, the court misapplies the substantial parent-child relationship factor to the issue raised by this case.
*695The court errs too by addressing the issue before it as though the court were writing on a clean slate, which it is not. The policy question has been addressed by the Legislature and for that reason is not open to the court. When the elected representatives of the people have declared the Commonwealth’s policy on a matter within their jurisdiction, the court exceeds its lawful powers by announcing an inconsistent policy. General Laws c. 209C (1988 ed.) provides for the rights of children born to parents who are not married to each other. Section 5 (a) provides with respect to complaints to establish paternity that such a complaint may be commenced by, among other persons, the putative father, “provided, however, that if the mother of the child was or is married and the child’s birth occurs during the marriage or within three hundred days of its termination by death, annulment or divorce, complaints under [c. 209C] may not be filed by a person . . . alleging himself to be the father unless he is or was the mother’s husband at the time of the child’s birth or conception.” It is true, as the court asserts, that G. L. c. 209C, § 5 (a), expressly bars a putative father in the situation of this plaintiff only from bringing an action “under this chapter”; that is, under c. 209C. But the social policy that motivated that enactment is quite clear: namely, that the unitary family traditionally respected by society and sought to be protected by the Legislature includes the family of the mother, her husband, and the child, and does not include the mother, child, and the mother’s lover. The Legislature has made clear that the policy of this Commonwealth is to withhold from a plaintiff a judicial forum in which to launch an attack on the legitimacy of a child and to otherwise disrupt family harmony.
The court decided P.B.C. v. D.H., 396 Mass. 68 (1985), in October, 1985, nearly four years before the United States Supreme Court decided Michael H. v. Gerald D., 109 S. Ct. 2333 (1989). Perhaps, as I discuss below, it is more significant that P.B.C. v. D.H., supra, was decided approximately eight months before the Legislature enacted G. L. c. 209C. See St. 1986, c. 310, § 16 (effective July 22, 1986). In *696P.B.C., the plaintiff contended that he had “a right to an adjudication of whether he [was] the father of a child conceived while the child’s mother, the defendant, was married to another man.” Id. at 68. We held that “in the circumstances of [that] case he ha[d] no such right.” Id. The “circumstances” were as follows: The child was conceived while the mother was married to a man other than the plaintiff. A divorce followed. The child was born the day after the divorce became final. The child lived continuously with the mother, and never with the plaintiff, who was denied access to the child by the mother after he filed his complaint asserting paternity. The mother and her former husband remarried the day after the complaint was filed. The child’s birth certificate listed the husband as the father. The husband never denied that he was the father, and, beginning with the month in which the complaint was filed, the mother, husband, and child lived together continuously.
Fully aware of Stanley v. Illinois, 405 U.S. 645 (1972), the court concluded in P.B.C. that, in the circumstances of that case, the plaintiff not only had no constitutional right to an adjudication of paternity, but that he also had no such right “as a matter of public policy.” Id. at 71-72. Because the Legislature had not yet directly spoken to the question in 1985, it was appropriate for the court to declare policy with respect to whether the Commonwealth should provide a forum to hear paternity cases instituted by a putative father when the child’s mother was married to another man at the time of conception or birth. The policy declared by the court was based on the Commonwealth’s “legitimate and strong interests in ‘the strengthening and encouragement of family life for the protection and care of children,’ G. L. c. 119, § 1 (1984 ed.), and in affording legitimacy to children. Powers v. Steele, 394 Mass. 306, 310 (1985).” Id. at 73. “Denying a plaintiff the right to establish his paternity in the circumstances of [that case],” the court said, “promotes [those] interests.” Id.
General Laws c. 209C, § 5 {a), provides in relevant part that, “if the mother of the child was or is married and the *697child’s birth occurs during the marriage or within three hundred days of its termination . .. complaints under [that chapter] may not be filed by a person . . . alleging himself to be the father unless he is or was the mother’s husband at the time of the child’s birth or conception.” That provision gives every appearance of being not only a legislative adoption of the public policy expressed in P.B.C. eight months earlier, but of an adoption of that policy without limitation to the precise circumstances of that case. The principal thrust of the policy announced in P.B.C. was that the Commonwealth’s interest in affording legitimacy to children, and in strengthening and encouraging family life for the protection of children, demands that a plaintiff not have standing to contend that a child whose mother was married to another man at the time of conception or birth is the plaintiff’s child. The Legislature has expressed that policy in G. L. c. 209C, § 5 (a). For that reason, I dissent from the court’s decision.1
If, contrary to the views I have expressed, the question of public policy were open to the court, I would strongly disagree with the policy declared by the court because it is antithetical to the Commonwealth’s legitimate interest in promoting family harmony for the care and protection of children and affording legitimacy to children whenever possible. I would not accept the proposition that it is sound public policy to recognize a man’s interest in maintaining a relationship with the child that he claims to have fathered by an adulterous, and therefore criminal, see G. L. c. 272, § 14 (1988 ed.), relationship with the child’s mother at the expense of making the child illegitimate and disrupting a “unitary family.” It seems to me strange public policy to declare adultery to be so contrary to public policy as to be criminal, and yet to reward the adulterer by giving him the right to disrupt the child’s family life.
I note that the court does “not address the issue of what rights this plaintiff may have if he succeeds in establishing paternity.” Ante at 691. I suggest that that issue is critical to the policy question the court addresses. Surely, the Commonwealth ought not provide a forum to determine the relationship between the plaintiff and a child he alleges is his unless certain parental prerogatives will follow. The critical question is whether the Commonwealth ought to award substantive parental rights to someone who, like the plaintiff, claims to be the “natural father of a child conceived within and born into an extant marital union that wishes to embrace the child.” Michael H. v. Gerald D., 109 S. Ct. 2333, 2344 (1989). “We are not aware,” writes Justice Scalia, “of a single case, old or new, that has done so.” Id. As I see it, as to this matter, Massachusetts should not go first.