concurring and dissenting.
I agree with the Majority that this case should be remanded, but, for the reasons presented below, I am unable to completely join in the Majority’s decision.
*253The Majority recognizes that “separation, divorce, and children born during marriage to third party fathers is [now] relatively common, and it is considerably less apparent that application of the presumption [of paternity] to all cases in which the child was conceived or born during the marriage is fair.” Op. at 181. I agree with this assertion.
However, despite the Majority’s recognition of this disparity between practical reality and legal rule, they have chosen nonetheless to preserve the “two great fictions of the law of paternity”—the presumption of paternity and paternity by estoppel. Op. at 180. The Court does hold that the presumption will no longer apply in cases where the policy it embodies would not be forwarded but, with regard to estoppel, today’s decision represents no break with prior case law.
I am unable to join in this approach because I believe that both the presumption of paternity and paternity by estoppel should no longer be strictly applied, as they have been in the past. In light of the changed, and increasingly fluid, nature of the family, and the increased rates of divorce and separation, these legal fictions have become less reflective of social reality. They are now more problematic than useful, and more likely to lead to unfair results. Thus, I agree with the Majority that when the reason for a law ceases, the law should also cease, but I do not join in today’s decision because, unlike the Majority, I believe that the time has come to take this principle to its logical conclusion in the law of paternity.
I believe that the better course of action in these cases is to allow the trial court to determine paternity on a case-by-case basis, unburdened by the obligatory application of a presumption or an estoppel theory. These doctrines have acted as an obstacle to the discretion of the trial court to order blood testing of the parties, the single most valuable technique available to a court in determining parentage. Abandoning their strict application would remove this obstacle and allow the trial court to order blood testing of both the alleged father and the presumed father. The benefit of this approach is of course that the trial court is not precluded from considering test results representing, in essence, conclusive evidence of *254paternity,1 but is free to acknowledge this evidence, along with such concerns as the maintenance of an existing family unit, if any, and the promotion of the interests of the child, in the course of arriving at an equitable result.
Moreover, I do not believe that abandoning the obligatory application of these two doctrines in favor of the judicious use of blood testing will necessarily result in any more strain on a marriage unit than would, for example, forcing a cuckolded husband, because of the presumption, to care for a child he knows is not his—a situation which would strain both the marriage and the husband’s relationship with the child. Blood testing would also work to eliminate situations where a man is deceived into believing he is the father and is then made to bear legal responsibility, by reason of estoppel, for a child that is not his.
It cannot be ignored, however, that blood testing impacts on an individual’s right to privacy and therefore may not be compelled without a balancing of the privacy interests of the one whose blood sample is sought as against the needs and interests of those seeking the test. See John M. v. Paula T., 524 Pa. 306, 316-17, 571 A.2d 1380,1385, cert. denied, 498 U.S. 850, 111 S. Ct. 140, 112 L.Ed.2d 107 (1990); see also Commonwealth v. Sell, 504 Pa. 46, 470 A.2d 457 (1983). The “good cause” requirement found in Pa. R.C.P. 4010(a) embodies this type of balancing.2 Rule 4010(a) states:
When the mental or physical condition (including blood group) of a party, or of a person in the custody or under the legal control of a party, is in controversy, the court in which the action is pending may order the party to submit to a physical or mental examination by a physician or to produce *255for examination the person in his custody or legal control. The order may be made only on motion for good cause shown and upon notice to the person to be examined----
Pa. R.C.P. 4010(a).
I believe this “good cause” requirement provides a workable standard to guide a court’s determination whether to compel blood testing.3 “[T]he requirement ... is not met by mere conclusory allegations of the pleadings or by mere relevance of the physical or mental condition to the case, but rather, requires an affirmative showing by the moving party that good cause exists for ordering the examination.” Goodrich Amram 2d § 4010(a):10, quoted in Uhl v. C.H. Shoemaker & Son, Inc., 432 Pa.Super. 230, 239 n. 1, 637 A.2d 1358, 1363 n. 1 (1994) (Beck, J., dissenting); see also Schlagenhauf v. Holder, 379 U.S. 104, 85 S.Ct. 234, 13 L.Ed.2d 152 (1964) (discussing the “good cause” requirement of Fed.R.Civ.P. 35, from which Pa. R.C.P. 4010 is drawn). If good cause is shown for the testing of either the alleged or the presumed father, I believe that he should be tested, despite the presumption of paternity or the presence of facts suggesting a finding of paternity by estoppel.4
*256Abandoning the strict use of these doctrines would allow our courts to examine the situation presented, to compel blood testing if the appropriate showing is made, and to weigh the competing factors in order to reach a just result in each case. Given the realities of marriage, separation, and divorce today, I believe a flexible, case-by-case approach to paternity issues, acknowledging and benefitting from the relative certainty of blood testing, is simply more preferable than a system characterized by the strict application of overarching and outdated legal fictions that can lead, as the Majority admits, to unfair results.
Thus, I would also remand this case to the trial court, but for blood testing, not a hearing on estoppel. Since Audrianna was conceived while the Brinkleys were married, and because good cause exists, it would seem reasonable to test George Brinkley first. If he is Audrianna’s father, the case would end. If he is not, Richard King should then be tested. If Mr. King is shown to be Audrianna’s biological father, I believe, given the facts of this case, that he should then be made her legal father.
It is true that in some cases the answers provided by blood testing will perhaps not be easy for all parties to accept. Despite this, it is my belief that the clarity and finality provided by a case-by-case approach involving blood testing outweigh this concern and make such an approach more desirable than the current system. Accordingly, I am unable to join in the language of the Majority’s decision, but I do join the Court’s remand.
. Blood tests have been held to be less than 100% certain. See John M. v. Paula T., 524 Pa. 306, 316, 571 A.2d 1380, 1385, cert. denied, 498 U.S. 850, 111 S.Ct. 140, 112 L.Ed.2d 107 (1990); Smith v. Shaffer, 511 Pa. 421, 515 A.2d 527 (1986). Despite this, I would suggest that they are extremely probative.
. "Good cause and notice are intended to protect parties against undue invasion of their rights to privacy.” Pa. R.C.P. 4010, Explanatory Note (2); see McGratton v. Burke, 449 Pa.Super. 597, 601-02, 674 A.2d 1095, 1097 (1996).
. Authority to compel blood testing is also found in section 5104(c) of the Uniform Act on Blood Tests to Determine Paternity, 23 Pa. Cons. Stat. § 5104 (1991). Section 5104(c) states in relevant part:
[i]n any matter ... in which paternity ... of a child is a relevant fact, the court, upon its own initiative or upon suggestion made by or on behalf of any person whose blood is involved, may or, upon motion of any party to the action ..., shall order the mother, child and alleged father to submit to blood tests.
This section authorizes the testing of an alleged father, but has been interpreted as affording no right to the alleged father to compel the testing of the mother’s husband—the presumed father. See John M. v. Paula T., 524 Pa. 306, 315, 571 A.2d 1380, 1385, cert, denied, 498 U.S. 850, 111 S.Ct. 140, 112 L.Ed.2d 107 (1990). Because I believe that such presumptions should no longer be applied in strict fashion in the law of paternity, I believe Rule 4010(a) provides the better standard for determining whether blood tests should be ordered. The Rule can be applied uniformly, and its requirements recognize and protect individual privacy interests.
. I would allow testing not only to identify a man as the biological father, but also to show that a man could not be the father. In other words, blood testing is as probative of a lack of biological connection as *256it is of paternity, and I believe it should be employed to establish either status.