Orthodox and Reform rabbis yesterday spoke about sexual ethics in contemporary Jewish life at a speech sponsored by Harvard-Radcliffe Hillel.

Each rabbi advised students to refrain from pre-marital sex but acknowledged that sexual and religious views have changed.

Reform Rabbi Roland Gittelson said that although Judaic ways of viewing sex must remain open to an "expanding world of knowledge," he voiced caution about having sex too often or too early before marriage.

"Pre-marital sexual intercourse can impair the ultimate objective of a physical and spiritual relationship," said Gittelson. "Sex should be the spiritual and physical culmination of marriage."

Love First

"When love comes first, sexual intercourse not only expresses that love, but reinforces and invigorates it," he said.

Orthodox Rabbi Haskel Lookstein also said that sex should be the last step in a relationship. Although Jewish thought views physical love positively, sexual decisions must have a moral basis, said Lookstein, who is principal of the Ramaz School in New York City.

"A man must live within limits," Lookstein said. "We are free to choose, but we are not the only arbiters of our decisions. We must submit to a will that's superior to ours."

Aware that many students may ignore such advice, both Lookstein and Gittelson said birth control should be used and students should realize their human weaknesses when engaging in pre-marital sex.

If someone cannot resist their sexual urges, one should at least realize that "proper sex" is defined by "the circumstance and the person," said Lookstein.