Despite its drawbacks, the ``best interest'' standard is quite malleable and allows the judiciary to respond to changing situations, social mores, and values. This standard also offers the essential virtues of adaptability and flexibility.52 Additionally, ``our common law system appears designed to promote the exercise of discretion.''53 Decision-making under common law is designed to encourage doctrinal flexibility and also to enable judges to conform a rule to suit each particular case, thereby allowing fine distinctions to be made among individual cases to ensure that justice can be achieved.54
Moreover, because of the often imprecise language used in case and statutory law, not to mention within the United States Constitution, discretion is necessary to interpret law.55 It is virtually impossible for lawmakers to write a rule that will anticipate every problem the rule intends to solve.56 Rules can malfunction and may have drawbacks.57 Discretion allows a judge to deal with complex bodies of law, correct errors or omissions, promote the intent of the legislative body, and seek justice.58 Further, issues of diversity, to which the United States has become increasingly more attentive to, may also be considered.
Despite the utility of discretion in decision-making, its ultimate legitimacy relies upon how closely it comports with the rule or law in question. Also, discretion is not as unbridled as it used to be. It is limited by a multitude of constraints, including case precedent and statutes.59 Further, the child's ``best interest'' principle operates not exclusively to, but rather in conjunction with, case precedent, rights, rules of law, guidelines, and presumptions. This is important since laws are created by rule makers who are in a better position to decide what justice is because legislators are able to acquire a full range of information about problems and societal concerns. Laws also legitimize decisions, suppress differences of opinion, treat similar cases alike, and serve a planning function. This function allows people to know in advance how a case will likely be decided.60
While some argue for developing universal criteria for determining a child's best interest,61 other influential critics do not. For example, one critic argues that state-prescribed views of a child's best interest is not acceptable, since it is impossible to develop a view that does not ``mindlessly refer to the majority's [or the judge's] preferences.''62 While this criticism is valid, this standard is deeply rooted in American law and it is unlikely that the discretion afforded to the judiciary in making ``best interest'' determinations will be abolished.