"It's in the nature of getting old that you don't realize that you're getting old," says Kenan Professor of Government Harvey C. Mansfield '53. "When you add the condition of senility, this is all the more the case."

Yet, administrators and Faculty members both say the issue is complicated by the fact that older professors are frequently the most distinguished in their fields.

"You have professors who are very much the established leaders in their field, and who are still available to serve as mentors and teachers, as advisors to the generations of students and scholars coming up after them," says Assistant Dean of FAS for Academic Planning Elizabeth Doherty.

That means the oldest members of the Faculty can often contribute significantly to their departments--even as the natural slow-down of age sets in, some Faculty members say.

"It's very much like in a family. The older people have something to contribute, and the younger people have something to contribute," says Mangelsdorf Professor of Natural Sciences J. Woodland Hastings.

All I Want Is A Carrel

Some departments have been affected disproportionately by the lifting of the mandatory retirement age.

Just 6 percent of professors in the humanities who have reached the age of 70 since 1993 remain on active service to the Faculty. More than 58 percent of professors in the same category in the natural sciences continue to teach.