CHICAGO (STMW) — A federal judge on Thursday threw out a civil suit brought by a white Chicago Public Schools teacher who alleged his black principal and CPS violated his civil rights by disciplining him for using the n-word in a “teachable moment” with sixth-grade students.

Lincoln Brown, 48, was suspended without pay for five days in 2011 for using the n-word in front of his majority African-American class at Murray Language Academy after one of his students passed a note to a girl with rap lyrics including the n-word.

His five-day suspension was later upheld by a CPS hearing officer who ruled that Brown had “engaged in inappropriate discussions with sixth-grade students during instructional time.”

Brown sued his principal, the Board of Education and the city of Chicago, alleging that his First and Fifth Amendment rights were violated for attempting “to teach his class … an important lesson in vocabulary, civility and race relations.”

In Thursday’s ruling, U.S. District Judge Manish Shah upheld the board’s discipline of Brown, rejecting any notion that the teacher’s constitutional rights were violated.

“Public employers can regulate the speech of their employees without regard to First Amendment limits when the speech at issue is uttered in the course of the employee’s duties,” Shah wrote in a 15-page opinion. “There is now no dispute that teachers may not use racial, cultural and ethnic epithets in the classroom; this policy was in place before Brown’s conduct in this case; and Brown knew it.”

Brown could not be reached for comment Thursday.

His attorney, William Spielberger, said his client intends to appeal.

“The judge seems to agree that the Chicago Board of Education has banned the use of a number of books, not just ‘Huckleberry Finn,’ but also ‘To Kill A Mockingbird,’ ‘Lord Jim,’ ‘Lord of the Flies,’ etc.,” Spielberger said, calling the ruling an injustice considering Brown’s background.

Brown’s father, Bernard Brown, former dean of Rockefeller Chapel at University of Chicago, was a supporter of the civil rights movement and marched with the Rev. Martin Luther King Jr.

Brown’s parents named him after President Abraham Lincoln; he was in a minority of white students growing up at Kenwood High School, and taught for many years in schools serving black children near Robert Taylor Homes, Spielberger pointed out.

“Lincoln Brown teaches courses on civil rights, and right after this incident, he would normally show a video of his own father marching with MLK in Marquette Park, and the crowd shouting ‘n lover’ at him,” Spielberger said. “This ruling appears to say that Lincoln Brown cannot show this video to his students or anyone in the CPS system because of the use of the word. And I think that’s a tragedy.”

Brown had argued in his lawsuit that he was attempting to teach his 11-year-old students the perils of racism. In a 2012 Chicago Sun-Times interview, he said he was being punished for denouncing an ugly slur that most sixth-graders have heard many times.

“It’s ridiculous to believe that sixth-graders aren’t exposed to this language, not only in music but in their everyday lives . . . It’s so sad — if we can’t discuss these issues, we’ll never be able to resolve them,” Brown said at the time.

He said he had been discussing the use of the racial slur in “Huckleberry Finn” in an attempt to show “how upsetting such language can be,” but that just as he used the n-word, the school’s principal walked into the classroom. The principal accused Brown of ”using verbally abusive language to or in front of students” and “cruel, immoral, negligent or criminal conduct or communication to a student, that causes psychological or physical harm” in violation of CPS policy.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2015. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)