In a six-page letter released Sunday morning, philosophy professor Thomas Pogge refuted allegations of sexual harassment and sexual assault made against him in a Friday Buzzfeed News article.

Pogge focused his rebuttal on the claims made by one particular student, Fernanda Lopez Aguilar ’10, who has accused him of sexually harassing her during her senior year, while he was her senior thesis advisor, and also sexually assaulting her on a trip immediately after her graduation. In his first public response to the allegations, Pogge offered five counterpoints, including that Lopez Aguilar had written him “enthusiastic e-mails” after the alleged misconduct occurred, that Lopez Aguilar had provided differing accounts of the alleged misconduct and that, after an investigation, Yale’s adjudicative panel had found him not guilty of sexual misconduct.

“My response, in brief, is that none of the alleged misconduct ever took place,” Pogge wrote in the letter, which was published on a yale.edu WordPress platform. “I doubt I will be able fully to convince many of you in this forum. But I can provide a substantial amount of evidence that should easily suffice to convince you to at least suspend belief until these allegations can once more be adjudicated in a proper judicial forum.”

According to documents Lopez Aguilar provided to the News, she did change her account of Pogge’s alleged actions between 2010 and 2011. In her 2011 filing with the University-wide Committee on Sexual Misconduct, she  claimed only that “sexual harassment occurred both before and after her graduation” and that “that Mr. Pogge withdrew an offer of employment as a Global Justice Fellow after Ms. Lopez refused his alleged sexual advances.” She did not claim that Pogge sexually assaulted her.

Claims of sexual assault first formally appeared in a 2014 pre-action letter filed against Yale by the British law firm McAllister Olivarius. Lopez Aguilar told the News Sunday night that she had not initially included accusations of sexual assault because she was embarrassed and felt she had provided adequate information to Yale’s adjudicative panel to warrant punishment for Pogge.

“I didn’t include those bits that were the most humiliating to me,” Lopez Aguilar said, referring to the alleged sexual assault. “They were embarrassing, and I thought I had enough evidence to show this was unwelcome conduct.”

Pogge denies that any of the alleged misconduct ever took place, and he wrote that Lopez Aguilar’s 2011 UWC filing contains “various provable falsehoods and inconsistencies that undermine her credibility.”

Pogge emphasized that after an investigation, the UWC concluded that Lopez Aguilar’s allegations of sexual harassment “were not credible.” But this is only partially accurate: According to a copy of the UWC ruling Lopez Aguilar provided to the News, the panel found that “there was insufficient evidence to support the charge of sexual harassment,” but also concluded that there was “substantial evidence that Mr. Pogge engaged in unprofessional conduct in his mentoring and supervisory roles.”

Still, Pogge wrote that when allegations that he had physically attacked Lopez Aguilar in mid-June 2010 arose, he “took and passed a polygraph test denying this and various other accusations.”

According to a copy of a polygraph test that Pogge provided to the News, the firm he contracted, The Center for Investigation and Forensic Polygraph, LLC, concluded that Pogge was “truthful” when stating that he had never touched Lopez Aguilar in a sexual manner, that he had never touched Lopez Aguilar’s body while he had an erection and that he had never touched Lopez Aguilar’s legs or breasts in a sexual manner.

In response to a Sunday evening inquiry from the News, the Center for Investigation and Forensic Polygraph would not confirm Pogge’s status as a client, citing confidentiality.

“I propose and offer to pay for additional polygraph tests of both parties’ conflicting claims with a mutually agreeable expert,” Pogge added in his letter. “I will continue to do what I can do, under the circumstances, to put these allegations to rest.”

Having questioned the differing versions of Lopez Aguilar’s claims, Pogge went on to detail what he called a “plausible alternative explanation” of the falling-out between the two.

“In retrospect, I believe that both of us were unnecessarily confrontational in our dispute and could and should have parted ways in a more civil manner,” Pogge wrote.

Pogge claims that the dispute centers around a fake job offer letter for his Global Justice Program, which he wrote for Lopez Aguilar in July 2010. Pogge said he wrote the “theoretical letter of employment” in order to help her secure a lease at the Taft Apartments, because she was unable to obtain an official offer letter from the Brookings Institute, where she had been offered a job. However, Pogge said his letter was “fake” and did not constitute an actual offer of employment. He acknowledged that writing the fake offer letter was “obviously wrong.”

Pogge said Lopez Aguilar then presented herself at his Global Justice Program in August 2010 with this fake job offer letter in an attempt to begin work.

“On the basis of Lopez Aguilar’s conduct and subsequent communications, I inferred that her plan was to force me into paying her a second full-time salary for the 2010-2011 year,” Pogge wrote. “My alternative to somehow find the money to pay her was to confess to Yale that I had provided her with a fake offer letter.”

But correspondence provided to the News by Lopez Aguilar complicates that explanation. On June 9, 2010, Pogge asked his assistant to add Lopez Aguilar’s biography to the Global Justice Program website’s list of fellows for fall 2010. In July emails that Lopez Aguilar sent to global health professionals, she described herself as a “Junior Fellow, Yale Global Justice Program,” copying Pogge on the correspondence.

In a Sunday email to the News, Pogge also disputed a separate incident of alleged sexual misconduct that occurred while he was a faculty member at Columbia University in the 1990s, an accusation that was also made public Friday. Pogge wrote in the email that he was accused in 1995 of telling a student that “our relationship has matured to the point where it ought to become sexual.” A copy of the McAllister Olivarius pre-action letter provided to the News by Lopez Aguilar contained affidavits from professors at other U.S. institutions that say Pogge was accused of sexual harassment at this time. The affidavits contend that as a result of the accusations, Pogge was barred from entering the philosophy building whenever his alleged victim had classes there. According to one philosophy professor cited in the affidavits, Yale was aware of these events when Pogge was hired in 2008.

Pogge did not address the incident at Columbia in his public letter. However, in his email to the News, Pogge said the accusation was “totally untrue.”

“It was not investigated further, but I was asked to keep my office door closed so that we would not make eye contact when she came to the department,” he said.

In his public letter, Pogge addressed what he claimed to be a “trial by Internet,” writing that participants in internet discussions often respond emotionally to the “inherent feel and plausibility of a speed-read story” without critically analyzing evidence presented by both sides.

Monica Wang contributed reporting.