Edward L. Bernays, 103, a public relations pioneer who helped transform the craft of press agentry into a sophisticated social science, died yesterday at his home in Cambridge, Mass. He had bladder cancer.

Mr. Bernays, who often was called "the father of public relations," advised and counseled the famous and powerful, including Presidents Wilson, Coolidge, Hoover and Eisenhower, industrialist Henry Ford, inventor Thomas A. Edison, ballet dancer Vaslav Nijinsky and singer Enrico Caruso.

He played a key role in arranging the publication in the United States of the writings of his uncle, the psychoanalyst Sigmund Freud, and in 1923, he wrote the seminal book on public relations, "Crystallizing Public Opinion." He taught the first college course on public relations at New York University in 1922.

To every dictionary and encyclopedia publisher he could find, he sent his definition of a public relations person: "An applied social scientist who advises clients or employers on the social attitudes or actions to take to win support of the publics upon whom the survival of the client depends." For years, he saw his definition published just as he wrote it.

Mr. Bernays's career in public relations spanned most of the century, beginning in 1913 when he was partner and publicity director of the agency that managed the concert tours of Caruso and the dance recitals of the Diaghilev Russian Ballet, featuring Nijinsky.

During Mr. Bernays's professional lifetime, public relations would become a multibillion-dollar business, its most skilled practitioners increasingly adept at molding and shaping public opinion through the use of surveys, scientific research, psychology and plain old-fashioned showmanship.

Mr. Bernays's method was uncomplicated. "I never visited newspapers. I created circumstances," he said. ". . . I told my clients what to wear, how to behave, how to greet visitors. I thought of it as an applied science."

To enliven the image of Calvin Coolidge, Mr. Bernays had singer Al Jolson and a trainload of starlets in for breakfast at the White House, then spread the story that the president had been the life of the party. The media played it that way.

To make beer drinking respectable when Prohibition ended, Mr. Bernays commissioned a home economist from the University of Iowa to do research on the beer drinking habits of the Founding Fathers and then publicized the results, linking the drinking of beer with American patriotism. He organized a letter-writing campaign to persuade state legislatures to authorize the sale of beer in grocery stores, and within six months 20 legislatures did so.

For Procter & Gamble, he organized a national soap sculpture contest to turn children's minds away from their fear of the burning sensation when soap got in their eyes when they bathed.

"It made it possible for the soap they hated to become something they loved, something that would gratify their creative instincts. Within a year, 22 million kids were involved in soap sculpture," Mr. Bernays said.

Mr. Bernays was born in Vienna. His mother was Anna Freud, the sister of the psychoanalyst. At age 1, he came to the United States, and he grew up in New York. He graduated from Cornell University.

During World War I, he served on the U.S. Committee on Public Information, and in that capacity, he accompanied President Wilson to the Paris Peace Conference at the end of the war.

Returning to New York in 1919, he opened an office that he described as specializing in "public relations counseling." He recruited Doris E. Fleischman, an assistant editor and a reporter at the New York Herald Tribune, to join him in the business, and in 1920, they were married. Over the years, their firm's corporate clients would include the likes of Allied Chemical and Dye Corp., Bank of America, Beechnut Packing Co., Columbia Broadcasting System, General Motors, United Fruit Co., Mutual Benefit Life Insurance and United Parcel Service.

Mr. Bernays counseled the government of India in 1947 on how best to promote the concept of democracy on the subcontinent, and he helped promote the agenda of civil rights and labor organizations and the American Civil Liberties Union.

In the 1930s, he spurned a feeler from Adolf Hitler, although some years later a newspaper correspondent interviewed Joseph Goebbels and reported to Mr. Bernays that he found a copy of "Crystallizing Public Opinion" on the propaganda minister's desk.

Among Mr. Bernays's other books are "Propaganda" (1928), "Speak Up for Democracy" (1940), "Public Relations -- A Growing Profession" (1945), "Engineering of Consent" (1955) and "Biography of an Idea: Memoirs of Public Relations Counsel Edward L. Bernays" (1965).

In 1962, Mr. Bernays and his wife relocated their business to Cambridge. She died in 1980. Until recent years, he had continued to give advice on public relations matters.

Survivors include two daughters, Doris Held and Anne Bernays, both of Cambridge; six grandchildren; and four great-grandsons. CAPTION: EDWARD L. BERNAYS