Laws must be justified by and cannot be divorced from moral principles, world-renowned philosopher Jurgen Habermas told a near-capacity Sanders Theater crowd last night at the first of two Tanner Lectures on Human Values.

Devoting the annual Harvard speech series to his musings on the philosophy of law, the German theorist elaborated his thesis on the internal relationship between legal systems and ethics, presenting a direct challenge to countryman and fellow political philospher Max Weber.

Habermas attacked Weber's theory on the bases of legal rationality for failing to "take ethical formalism seriously." The early 20th-century philosopher, Habermas said, "did not distinguish the influence of values from the moral ordinance of laws."

The speaker said legality does not derive from the rational but rather from the moral, adding, "Morality no longer is suspended above law."

Habermas was introduced by President Derek C. Bok and addressed such Harvard notables as Conant University Professor John Rawls, Government Department Chairman Robert D. Putnam, Ford Professor of Social Sciences Daniel Bell, and Professor of Law Duncan M. Kennedy. A group of protesters chanted "Divest" as Bok called the lecturer to the floor.

Habermas, a professor of philosophy at the University of Frankfurt, is the author of eight books, including "Knowledge and Human Interest," "Towards a Rational Society" and "The Philosophical Discourse of Modernity."

He has served as Director of a Max Planck Institut in Starnberg and Munich and has held a host of teaching positions at institutions such as the New School of Social Research, theUniversity of Heidelberg, Wesleyan University, theUniversity of Pennsylvania, the University ofCalifornia and the College de France.

Last night's lecture marked the beginning ofwhat Bok termed a "substantial visit" by Habermasto Harvard. Because Habermas was fatigued from histrans-Atlantic flight earlier in the day, Bokpostponed the question-and-answer portion of thelecture until tonight, when the philosopher willdeliver his second and final lecture.

The speech, at 8:15 in Sanders Theater, isentitled "Some Considerations on the Meaning ofthe Rules of Law.