Last year, while I was teaching at Princeton University on the politics of journalism, a lot of class time was devoted to a debate on the appointment of Princeton's very first full-time tenured professor of bioethics, Peter Singer.

An Australian, Singer was a principal founder of the animal liberation movement and is a former president of the International Association of Bioethics. What led to our discussion in class -- and to various protests outside the university against his appointment, which starts this month -- is that he is also an advocate of infanticide. Not of any infant but of severely disabled infants.

In class, nearly all of us agreed that in a university, a credentialed scholar should not be banned, no matter how controversial his views. But some of us wondered why Princeton chose this renowned apostle of infanticide and certain forms of euthanasia for so influential an endowed seat at, of all places, the university's Center for Human Values.

Singer often claims that his views have been misquoted, so I am quoting directly from his books. From "Practical Ethics": "Human babies are not born self-aware, or capable of grasping that they exist over time. They are not persons." But animals are self-aware, and therefore, "the life of a newborn is of less value than the life of a pig, a dog, or a chimpanzee."

Accordingly, from "Should the Baby Live?": "It does not seem wise to add to the burden on limited resources by increasing the number of severely disabled children."

Also in that book, Singer and his colleague, Helga Kuhse, suggested that "a period of 28 days after birth might be allowed before an infant is accepted as having the same right to live as others."

In "Practical Ethics," second edition, Singer makes clear that the parents, together with their physicians, have the right to decide whether "the infant's life will be so miserable or so devoid of minimal satisfaction that it would be inhumane or futile to prolong life."

As an example, he speaks of severe forms of spina bifida, which, he says, "can affect as many as one in 500 live births." He adds Down's syndrome, which also is not rare. Parents, by disposing of such infants, still may have a chance to have "another pregnancy, which has a good chance of being normal."

Singer has been influenced by Jeremy Bentham (1748-1832), the founder of modern utilitarianism. Bentham held that the foundation of morals and legislation should be, as Singer explains him, "to maximize pleasure or happiness and minimize pain or unhappiness."

Once killed, the disabled infant will be freed of pain. As an Australian, however, Singer may not be fully aware that in this country, he is advocating the commission of a crime.

Not that Singer himself has ever killed an infant, but he is telling his students to cast aside a point that Justice Harry Blackmun took great pains to make in his majority opinion in Roe v. Wade:

"The word, `person,' as used in the Fourteenth Amendment, does not include the unborn." But once born, there is indeed a person under the Constitution whose "right to life," Blackmun agreed, "would then be guaranteed specifically by the Amendment."

Singer does not focus only on preventing disabled infants from being miserable. As for euthanasia at any age, he writes in "Practical Ethics," second edition: "If there is no intrinsic difference between killing and allowing to die, active euthanasia [performed by a physician] should also be accepted as humane and proper under certain circumstances."

But that person, he makes clear, must want to be euthanized. Unless, he says, the patient lacks "the capacity to understand the choice between continued existence or non-existence." Then killing is appropriate.

In "Practical Ethics," Singer disputes Dr. Leo Alexander, who was an expert witness at the Nuremberg trials and later wrote that the crimes of the Nazis, before the gas chambers, "started from small beginnings" -- the acceptance that "there is such a thing as life not worthy to be lived." Singer believes Alexander misses the utilitarian point.

Princeton's Singer, by no means a Nazi -- three of his grandparents died in concentration camps -- does believe that some lives are not worth living. But Dr. Alexander's warning is ever more pertinent as legal assisted suicide, euthanasia and eugenics are gaining support from decent people who assume the practical-ethics right to judge others' quality of life.

Correction: In last week's column, "The Big Apple's Rotten Policing," I wrote that in New York, last year, 500 people a day were arrested, kept in holding cells, then released after prosecutors dropped the charges before a judge was involved. The number should have been 50 people a day. The total of unprosecuted arrests in that year remains 18,000.