Dr. Ruth Westheimer answered a lot of the old standards during her visit to Harvard Monday night.

Penis size, anxiety and the various pleasures of the prostate were among the topics raised by the crowd of more than 500 students and Cambridge locals who turned out to hear the good doctor's Science Center speech.

But Westheimer, known to most Americans simply as Dr. Ruth, didn't leave Harvard without tackling several of the hot political issues on campus: date rape and sexual harassment.

In a reception after her talk, Westheimer suggested what she thinks is the best method of avoiding date rape: talking before climbing into bed. Decisions regarding sexual intercourse should be made before a couple is under the covers, she said.

"I believe it has to be very clear to two people where they stand before they go to bed," Westheimer said. "If you don't want to have sex, you have no business being naked in bed with someone."

"A woman can't tease," Westheimer said, adding that "heavy petting" falls within her description of teasing.

"I don't think she can be in bed naked and not have discussed [sex] beforehand," Dr. Ruth said.

Westheimer said that either of the two partners could get "carried away," if a sexual liaison is not preceded by extensive talk.

"I think we have to be very, very careful to talk about these issues and what they mean," she said.

Dr. Ruth, who is internationally known for the sex therapy she offers in books and on radio airwaves, said that she acknowledges some of her views are "old fashioned."

Despite the controversy that has surrounded the College's disciplinary procedure in date rape cases, sexual harassment, and not rape, appears to be the current hot topic.

Westheimer said Monday night that the line between playful talk and sexual harassment is getting harder to draw.

"Using power for sex is wrong," she said. "To have sex under pressure like that is very sad."

Westheimer said that sexual issues, even between consenting adults, merit more consideration than they once did, in light of the AIDS epidemic.

"[Students] really have to think twice about with whom to start a sexual relationship," she said. "The specter of AIDS is terrible for young people."