Just a month and a half after beginning her Yale career, philosophy professor Susanne Bobzien has discontinued her teaching responsibilities this term because of an undisclosed illness, said Michael Weber, director of undergraduate studies in philosophy.

Almost two years after accepting a tenured position at Yale, Bobzien recently left her post at Oxford University to commence her teaching activities at Yale. As a result of the illness, Bobzien cancelled her spring seminar, “Vagueness and the Sorites Paradox” at the beginning of the term. But she decided to start teaching her lecture class, “Determinism and Freedom in Ancient Philosophy,” and continued to do so until last week, Weber said. As a replacement, the Philosophy Department hired Lawrence Vogel GRD ’89 from Connecticut College, where he continues to hold his post as chairman of that college’s philosophy department.

Students in the class said there were hints that Bobzien was not in perfect health. On one occasion, Bobzien began class by telling students that she might have to leave in the middle of the lecture, said Katie Burghardt ’05. Ultimately, Bobzien did not have to end early.

Burghardt said while that instance was slightly startling, she was unaware of the seriousness of Bobzien’s illness.

“It was a shock to have the class actually cancelled,” Burghardt said. “I think we’re all curious just to know what’s going on.”

After learning of Bobzien’s decision to discontinue her teaching, Weber said the University began searching for a replacement and ultimately hired Vogel, whose connection to Yale made him an attractive candidate.

“He’s very excited about being able to teach Yale students,” Weber said. “He thought they were quite an exceptional group of students.”

Weber praised Vogel’s experience and said students were excited to work with the new professor.

But students said they remain concerned during this time of transition. Because of Vogel’s prior commitments at Connecticut College, the class can no longer meet at its assigned time. Prior to Bobzien’s decision, the class met Tuesday and Thursdays from 2:30 p.m. to 3:45 p.m. But because it is difficult to accommodate all 25 students’ schedules, the class now meets on Tuesday nights from 8:00 p.m. to 10:30 p.m.

“We’re trying to accommodate as many students as we can,” Weber said.

The time change is also accompanied by a curricular change. While the original class focused exclusively on ancient philosophers, Vogel plans to focus on 20th-century philosophers in the latter half of the class, Weber said. For some students, the change was not welcome.

“There are some people who signed up to take an ancient philosophy class and there’s concern from them on whether they even want to take the class,” Burghardt said.

While Bobzien was known for her scholarly, British style of lecturing, Vogel leads more of a discussion-based class — a change students said they welcomed.

“I certainly liked having her as a professor and I would have been very happy if she stayed,” Burghardt said. “But I feel Professor Vogel is very promising.”

While it is unclear when Bobzien will resume her teaching activities, Weber said she still plans on grading her students’ papers.

“I do know that everyone was very anxious for her to join the department and considered her a great addition and I’m hoping she’ll be well as soon as possible,” Weber said.

Despite student concerns about the class schedule and syllabus, Weber said he feels the transition was smooth considering the nature of the switchover.

“Everyone is trying to help out as much as they can under these difficult circumstances,” he said.