Marvin E. Lewis, a former San Francisco Supervisor and one of the city's most respected trial lawyers, died Saturday in a rest home after a long illness. He was 84 years old.

He was also a major force in making Bay Area Rapid Transit a reality for commuters and a plaque at a BART station praises him as a "determined prophet."

He was a pioneer of the legal concept of psychic injury, arguing in a 1959 case that a female client became psychotic after falling through a wooden stairway at her apartment. He said the woman's fall was a fall from grace, psychologically speaking, and interfered with her religious upbringing. The woman, June Daimare, who had sued her landlord for damages, was awarded $101,000.

Mr. Lewis was perhaps best known for a 1970 case that the media called "The Cable Car Named Desire," in which a jury ruled in favor of a young dancer, Gloria Sykes, who claimed she lost her mental balance and became a nymphomaniac after a cable car accident. Ms. Sykes sued the city and a jury awarded her $50,000.