This episode's headline: Teen Abortions; Summit at Sea; Conversation. The guests include JAMES BOPP, National Right To Life Committee; JANET BENSHOOF, American Civil Liberties Union; JAMES CALLAGHAN, Former Prime Minister, Great Britain; EUDORA WELTY, Writer; CORRESPONDENTS: FRED DE SAM LAZARO; ROGER MUDD. Byline: In New York: ROBERT MacNeil; In Washington: JAMES LEHRER