Few undergraduates mangage to make it through four years and eight Core classes at Harvard without buying at least one course textbook written by their professor. Frequently more than one.

Take, for example, the students in Moral Reasoning 34, "Moral Perfectionism," taught by Cabot Professor of Aesthetics and the General Theory of Value Stanley Cavell. Of the 32 books required or suggested for the course, no less than seven are written by Cavell himself.

The total cost to students who buy all seven? Around $80.

But while few professors go to Cavell's extremes, the practice of scholars assigning their own books for courses they teach is a common one at Harvard.

Professors cite numerous reasons for their decisions to use their books for their classes. Some say they do it because students learn more when the text they read echoes and expands on the material covered in lecture. Others note that the `standard' texts for many academic disciplines are written by star scholars who teach at Harvard.

The fact that academics earn royalties for each and every new copy of their books bought by eager students, they say, has little to do with the practice.

"I'm certainly not getting rich off this," says Colette Daiute, an associate professor at the School of Education.

Standard author royalties are 15 percent of the publisher's price to bookstores, or around 12 percent of the price charged individual consumers, according to spokespersons for Addison-Wesley and Harcourt Brace Javonovich, two prominent publishers of academic books. Authors with a proven track record of strong sales, however, can command higher royalties, they added.

But because the market for most academic books is extremely limited, royalties tend to be minimal.

Jones Professor of Classical Greek Literature Gregory Nagy, who regularly assigns his own The Best of the Achaeans to his perennially popular Literature and Arts C-14, "The Concept of the Hero in Greek Civilization," said that his earnings from the book's sales are "infinitesimally small."

"I wouldn't call it popular," Nagy says of the current edition. "It gets bought," he adds, "especially by graduate students."

Nagy adds that the book--which some undergraduates have simply left in the plastic wrapper for an entire semester--was downgraded to optional reading for the most recent edition of his course this past fall.

But when an academic book makes it into the lucrative market for national textbooks, profits can skyrocket.

"Best-selling textbooks make a lot of money," says Anthropology Department Chair Irven DeVore. "It's a cash cow, there's no doubt about it."

"The real money, of course," he elaborates, "is not at the college level but at the high school and elementary level."