BRUNSWICK, Maine — The ACLU of Maine sent a letter to the Brunswick School Department late last month claiming that a fifth-grade teacher at Harriet Beecher Stowe Elementary School had “blatantly unlawfully” taught a biblical interpretation of creation under the guise of “astronomy” in violation of the U.S. Constitution and state curriculum guidelines.

Lou Sullivan, a longtime teacher in the Brunswick system, “is plainly teaching intelligent design in class,” ACLU of Maine legal director Zachary Heiden and senior staff attorney Heather L. Weaver wrote in a March 27 letter to Superintendent Paul Perzanoski that carried the subject line “Creationism at Harriet Beecher Stowe Elementary School.”

The theory of “intelligent design” holds that the universe and living beings are so complex that they must have been created by an “intelligent” force typically identified as a deity. Conservative Christian opponents of teaching evolution have advocated that “intelligent design” be taught as an alternative.

Perzanoski in a phone interview Tuesday dismissed the basis for the complaint.

“We categorically deny we were teaching anything about creationism,” he said, adding that many of the allegations “transpired from a discussion [Sullivan] had with the kids” during which they asked him about his personal beliefs.

The March 27 letter to the school quotes a Jan. 9, 2015, email to parents in which Sullivan wrote of the week’s science lesson.

“This week it was a discussion on how the universe was created,” the email reads. “After discussing the Big Bang and Intelligent Design, I realized that my worksheet for the lesson was terribly inadequate. The class helped me revise the page so this it is updated and much improved. I can’t wait to use it next year!”

According to the ACLU letter, Sullivan wrote in response to an inquiry about the lesson, “Basically, the ‘Intelligent Design’ discussion is something I include each year when I present my lesson on the Big Bang and other theories. I began the discussion after years of speaking with families [who] have very different beliefs about how the universe was created. I often heard concerns about how this lesson was presented. I try to allow all students to share what they believe about the creation of the universe. We usually have students (as well as nationally known scientists) who are adamant that ‘I believe God created the universe’ and others who are adamant that ‘I don’t think God exists.’”

The ACLU of Maine cites concern that the Brunswick School Department’s science curriculum includes an “Essential Knowledge” unit that notes, “There are many theories, myths and legends about how the universe began.”

“Standing alone, this ‘Essential Knowledge’ item is troubling in the context of a science lesson,” the letter states. “But Mr. Sullivan’s worksheet on Astronomy (entitled, ‘THE BIG BANG (and other creation theories)),’ goes even further, referring to “[s]ome creation theories”—‘Big Bang’ and ‘God made the universe’.”

The U.S. Constitution prohibits an effort to teach religious doctrine in science classes, and according to the ACLU of Maine, that prohibition encompasses intelligent design or giving “equal time” to that topic.

The letter suggests that Sullivan “employs a tactic often used by proponents of creationism and intelligent design: miseducating and confusing students about the meaning of a ‘theory’ in the scientific context.

According to the letter, one of the essay choices in Sullivan’s astronomy lesson asks students, “Tell whether you believe the universe could have been created by the Big Bang. Give good reasons to back up why you do or do not think it could have happened. You may want to include several of the steps of the theory, or include another theory or belief as part of your answer.”

But according to the ACLU of Maine, “any competent science educator” should be aware that a scientific theory is well-tested and well-substantiated, and “thus asking students whether they ‘believe’ the universe could have been created by the Big Bang is precisely the wrong question.’”

The letter demands that the school department “put an immediate end to the practice of teaching religious doctrine in science class,” and take steps to ensure teachers “understand why teaching creationism and intelligent design is wrong from a pedagogical and a constitutional perspective.”

The ACLU of Maine will continue its investigation to determine whether additional action, such as litigation, will be taken should the district fail to comply.

Sullivan did not return a message left at his home Tuesday afternoon.

Perzanoski said the district is already collecting requested information from the 28 K-12 teachers in the district, including all lesson plans referring to or relating to the origin of the universe or evolution.

Administrators also plan to review worksheets, exams and videos, as well as all school policies related to teaching about the origin of the universe or evolution.

The superintendent said curriculum he has reviewed so far has no mention of creationism or intelligent design. And he said the letter from the ACLU of Maine was full of incomplete emails in responses to discussions with students.

He said that school officials addressed in January a complaint from a parent, and met with the parents and Sullivan.

“When you are discussing the Big Bang theory and kids bring up other things, teachers as they’re discussing those things with kids answer questions,” Perzanoski said. “That teacher was not teaching creationism. He did not get up in the class and teach intelligent design.”

As a result of the complaint and the letter, Perzanoski said, “The teacher cannot, will not, answer kids questions directly when it deals with God, unfortunately — that’s an unfortunate result of all this — and will try to be as delicate as possible in making sure we don’t offend anybody.”

The ACLU of Maine has requested that the school department provide requested materials to them by April 30. Heiden said Tuesday he awaits the documents to see if the situation has been resolved.

“Teaching about religion in history or social studies class is important, but teaching religious views as science is not only wrong — it is unconstitutional,” Heiden said in an email to the Bangor Daily News. “Intelligent design is a Trojan Horse for bringing creationism into the science classroom, where it does not belong.”