David Parker and Robert Wirthlin are wrong, and the sooner Catholics understand this, the better.

Parker and Wirthlin sued the Lexington Public Schools (LPS) because of a claimed infringement of their rights as parents.

When Wirthlin’s son, Joey, was in first grade, his teacher read aloud from a book called “King and King,” about a prince who is instructed by his mother to look for a princess to marry; but the prince is dissatisfied with all of the available princesses, and at last he “marries” another prince. The last page of the book shows the two men kissing.

Parker’s son, Jacob, brought home from kindergarten a “Diversity Book Bag,” which contained “Who’s In a Family?” a book that the School Library Journal describes in this way:

“Simple declarative statements move readers from one family configuration to the next, from single children to single parents to same-sex couples. Here and there animal families are juxtaposed with the human, presumably to show that certain situations are natural.”

The book’s professed aim is to teach that it is perfectly normal for same-sex couples to raise children.

The fathers of these children claim that LPS infringed their constitutional right to educate their child as they see fit. Since both men are Christians, they also claim that LPS infringed their right to free exercise of religion. They argue that current Massachusetts Law (Chapter 71: Section 32A) requires that, where practicable, parents be notified in advance of sex education discussions and be allowed to opt-out. Thus, they say, LPS should have notified them in advance about anything that promotes homosexuality or a homosexual lifestyle.

But such arguments, although understandable, are untenable given the Supreme Judicial Court’s (SJC) mandate recognizing same-sex “marriage.” It is crucial for Catholics to appreciate this.

The SJC decision is based on an analogy between the gay rights movement and the civil rights movement. In essence it holds that differences in sexual orientation are as irrelevant to marriage, or any other social role, as differences in skin color. Anyone who thinks otherwise is an irrational bigot, whose views need to be discouraged and eventually extinguished.

The analogy is misguided to be sure. But because of the SJC decision, that analogy has now become guiding law for all public institutions in Massachusetts, including the public schools. Thus, to see whether the lawsuit of Parker and Wirthlin has any merit--according to current law--one should consider whether a comparable claim advanced on behalf of a racist bigot would have any merit.

Imagine, if you can, that someone believed a religion according to which people with black skin are less worthy humans than those with white skin; in particular, according to this religion, white-and black-skinned persons should never intermarry. This man has a son who attends kindergarten in the Lexington Public Schools. One day his son brings home in his “Diversity Book Bag” a book which depicts interracial marriages. The professed aim of this book is to get children accustomed to the idea that interracial marriages are acceptable and normal.

The father objects strenuously that his right to raise his own children has been infringed -- The school replies, correctly, that this right is not absolute, and, in particular, the school has the obligation to teach students about the equality of the races under Massachusetts law.

The father next objects that his free exercise of religion has been infringed-- The school replies, again correctly, that LPS aims to make its schools “safe” for children of all races, and thus it has the educational goal of teaching all students about the acceptability of racial differences.

Finally, the father objects that, in depicting an interracial marriage, the book raises questions of human sexuality and sex education, and thus he should be given the option in advance of excluding his children from initiatives promoting such a thing. To this the school district would reply, again rightly, that a book can perfectly well discuss marriage without discussing sex or sex acts.

“It is reasonable for public educators to teach elementary school students about individuals with different sexual orientations and about various forms of families, including those with same-sex parents, in an effort to eradicate the effects of past discrimination, to reduce the risk of future discrimination and, in the process, to reaffirm our nation’s constitutional commitment to promoting mutual respect among members of our diverse society.”

Thus wrote District Court Judge Mark Wolf, in his summary dismissal of Wirthlin and Parker’s complaint. Wolf’s reasoning is impeccable, once one accepts the analogy between sexual orientation and skin color. But, again, that analogy has been built into Massachusetts fundamental law through the misguided and rogue opinion of the SJC.

A perverse but fun exercise is to think through all of the ramifications of this analogy. For instance, the very words “mother” and “father” are clearly discriminatory; it is certain that the public schools will soon begin discouraging their use. Likewise, “Mother’s Day” discriminates against students who are raised by two men, and “Father’s Day” against students raised by two women. These holidays will be abolished in the public schools, just like Christmas. Also, books that teach the sacredness of marriage as between only a man and a woman -- including many classics of literature, such as “Romeo and Juliet” will eventually be looked upon with suspicion, on the grounds that they inculcate discriminatory attitudes from the past.

You think I’m joking? Is “King and King” a joke?

Michael Pakaluk is a professor of philosophy at Clark University who resides in Cambridge, Mass.