Harvard graffiti is an interactive pursuit. People respond to others' comments, tracing spidery lines of print down a wall's edge.

Often the dialogue ends with some sort of Marxist summation. In pre-med row, for example, a spiral of obscenities draws this comment: "Manifestations of anger in response to an oppressive university and society."

And in the Yenching Library women's bathroom, a debate on lesbianism ends with an attack on bourgeois society. "Wise up Harvard! Sexuality is the recreation of the leisure classes. The poor and homeless are too constrained by fatigue and lack of shelter to make sexual preference such an important is sue."

Commenting on society seems to be an age-old need. "It's not new," says Professor of Sociology James A. Davis. "There's medieval graffiti and there's Roman graffiti--it seems to be something about human nature."

Just what about human nature remains unclear. "Almost by definition, we don't know," Davis says. Maybe, he suggests, graffiti artists are "expressing passion, resentment--or trying to get a date Saturday night."

Bathrooms house some of the most passionate graffiti. Writers work through gender issues and deal with emotional crises in language of varying subtlety.

"My experience in men's bathrooms around the world is usually it's quite smutty," says Davis.

Others agree. "Often it's not even sexual, it's just perverse," says Daniel E. Smith '95. "They're sometimes just wacked out. Seriously, wacked out."

But the graffiti is still enticing. "I always read it," says C. Morgan Schmidt '94, who adds that he's occasionally tempted to upgrade the general tone.

"The only time I've ever been driven to write graffiti was when I though I could write good poems on bathroom walls," he says, leaning back speculatively in his chair. "I'm not against defacing things for a reason."

In the age of Robert Bly and the men's movement, macho grafitti displays may seem passe. Where's all the writing from the new, sensitive males? Not in Harvard bathrooms, evidently, where men tend to discuss sex and sexuality with violent overtones.

Comments in women's rooms usually are more affirming. The same issues--distress, sexual identity, relationships--are phrased in more gentle terms.

"I've been sitting here crying for 40 minutes," reads a wispy notation on the wall in the Yenching Library women's room. "I hate Harvard. I'd rather be any place else in the world. I know I'm whining about privilege but I don't care, I hate it. I want to go home. I hate it."

Other women rally to the cry. "You are not alone," one respondent writes. "I feel this way often. Good luck." Two other women suggest Room 13 as a source of support.

Men get a bad rap on these bathroom walls, where boyfriends tend to be viewed as oppressive.

"How does a woman maintain self-respect and be involved with a man?" one person writes.

In black, scratchy script, someone offers an ambiguous answer. "It is only by having respect for yourself that allows you to respect another."

Others sidestep the quicksand of emotional angst entirely. "I spent my summer as a life-guard," writes a peppy purple pen just below these outpourings, "and it was really fun!"

Both angst-ridden comments and happy reports of summer frolics help to humanize an often impersonal world, says Sarah T. Kuehl '92-'93, who is writing about graffiti for her senior thesis.

In the modern era, that may be graffiti's most important function. All we can do is inscribe our thoughts, anonymously, for others to read--at least until Harvard repaints the walls.