PRESIDENT BOK WOULD have us believe that human civilization is still in the Dark Ages. The portrait of Harvard he paints in Friday's open letter on "the ethical responsibilities of the university in society" is a dismal flash-back to medieval times, when colleges were walled fortresses, isolated from society. Bok would have us spring to the battlements, caldrons of boiling oil at the ready, whenever society's political turmoil and moral conflicts approach the gates.

In his more lucid moments, Bok knows better. No university can be an island, especially not Harvard. With its $1.5 billion worth of investments, with its direct conduits to the highest ranks of this country's political and business leadership, with its immense prestige as America's foremost repository and preceptor of knowledge and values, Harvard takes institutional stands every day.

And Harvard's stands influence our whole society. Justice Lewis Powell's majority opinion in the Bakke case, for instance, hinged on Harvard's friend-of-the-court brief. The Cambridge-Washington shuttle, institutionalized during President Kennedy's administration, shapes public policy to aid in education, tax rules on charitable giving, and myriad other areas.

The Harvard administration has never been shy about using Harvard's considerable influence in these areas. Its actions give the lie to Bok's rhetoric in Friday's letter about the role of a university. By equivocating, delaying, and finally coming out against any change in Harvard's investment policies, Bok has taken a stand.

Not to decide is to decide. Not to boycott Nestle products is to support Nestle. Not to rename the Engelhard Library is to endorse Engelhard's example of "public service." Not to pressure corporations to withdraw from South Africa is to support apartheid.

Bok writes that by adopting a position on moral questions, the University would establish an official orthodoxy that might silence debate and limit the "open-minded search for truth." But moral choices will have to be made: the Harvard Corporation's current orthodoxy, which sanctions investment in South Africa, bolsters the profits of the Nestle corporation, and glorifies a man who made his fortune in the mines of South Africa, is a more pernicious denial of free expression than the orthodoxy President Bok tries to scare us with. As of now, the seven men on the Harvard Corporation make decisions on moral issues for the Harvard community. Isn't it more likely that the current situation, not Bok's hypothetical case, inhibits "a junior faculty member hoping for tenure, a young administrator seeking a promotion, a full professor worrying about a raise in salary...from openly espousing a view contrary to the official doctrine of the university" as Bok put it? Intellectual freedom means more than having seven men run the University: why bother to speak out when no one will listen?

BOK'S LAST TWO ARGUMENTS--that taking moral stands might threaten Harvard's freedom from outside interference and endanger its financial base--are too vaguely presented in the letter to have much punch. Who is it that would interfere? Why would they do so? Just what are the financial costs of the moral positions Bok is so reluctant to adopt?

The recent statement by several faculty members and the South African Solidarity Committee suggests the costs to Harvard of divesting holdings in companies operating in South Africa may be far less than Harvard has estimated.

These are questions one hopes Bok will address in his next letters, which will deal with specific moral issues.

President Bok stated in his letter that the way a university "addresses these questions and the answers that it gives are inescapably a part of the moral education that it imparts to its students." Last April, Bok chose to stride across the Yard and zoom away in a car to avoid talking to students without the protection of a podium. The "moral education" Bok gave to Harvard students then was to evade those with whom one disagrees. And his letter teaches students to rationalize denying the moral consequences of their actions.