In one of the most important cases the Supreme Court will hear this fall, the Department of Justice has taken a stand, along with a number of influential people and organizations. All of them take specific, strong stances on the definition of sex and gender identity, which center around the questions both the LGBT activists, conservatives, and legal experts have been asking for some time: What is sex, who defines it, and what legal protections does it have?

In a brief filed with the Supreme Court, the Department of Justice said they believe transgender discrimination is not prohibited by Title VII of the Civil Rights Act of 1964. The Supreme Court will hear oral arguments in R.G. & G.R. Harris Funeral Homes Inc. v. Equal Employment Opportunity Commission in October to address the issue. The ACLU will argue on behalf of the transgender woman and the Equal Employment Opportunity Commission’s position, claiming the employee was fired because of her gender identity. R.G & G.R. Harris Funeral Homes maintains that the employee was fired after he transitioned from male to female because he did not wear sex-specific clothing, which is a company policy.

This particular brief is significant because the DOJ represents the Equal Employment Opportunity Commission, but their brief shows they will depart from the commission’s position that gender identity should be a protected category until Title VII’s sex discrimination clause. In the brief, the DOJ argues that Congress didn’t include transgender people and gender identity when Title VII of the 1964 Civil Rights Act was originally passed, and Congress has not passed any efforts to add gender identity to the statute. “Under this Court’s precedent, proving discrimination because of sex under Title VII requires showing that an employer treated members of one sex less favorably than similarly situated members of the other sex,” the Justice Department said in its brief.

The DOJ’s brief isn’t the only noteworthy opinion on the case. Paul McHugh is the University Distinguished Service professor of Psychiatry at the Johns Hopkins University School of Medicine and he filed an amicus brief “not to discuss statutory construction but to critically evaluate, on the basis of his clinical and scientific expertise” in support of the concept that gender identity and sex are not the same thing, which basically supports the funeral home's case. The brief reads that he “seeks to discuss the frequently heard claims about gender identity, which sometimes masquerade as science but are really ideological pronouncements not supported by scientific evidence.”

Just last week a brief was filed by a group of people who appear to have all undergone gender reassignment surgeries or transitioned to some degree, and warn others about the dangers of transitioning through hormone replacement or surgeries. In their brief, they too tackle the subject of gender identity, sex, and transitioning, rather than law. Both amicus briefs provide an insightful look into the world of those who treat or who have identified as a different gender from a cultural, rather than a legal, perspective.

This case will be to gender identity what Obergefell v. Hodges was to same-sex marriage. It will be interesting to see who else steps in to add a perspective to this controversial legal case.

Nicole Russell (@russell_nm) is a contributor to the Washington Examiner's Beltway Confidential blog. She is a journalist who previously worked in Republican politics in Minnesota.