He prepared at the Hun School and Lawrenceville. At Princeton he majored in English and graduated with honors. Ash was a columnist and book reviewer for The Daily Princetonian and Sovereign , and was a member of Terrace Club.
Ash joined the Navy in 1942 as an ensign and served in the Aleutians and the Solomon Islands. He separated in 1946 as a lieutenant.
After earning a law degree at Columbia University, he first joined Bankers Trust in the trust department, but left to become legal researcher and adviser to Sidney Schreiber and Jack Valenti, general counsel and president of the Motion Picture Association of America, respectively.
Ash also assisted attorneys across the United States in their representation of motion picture companies. Besides his legal scholarship, he devoted himself to the study of history, language, literature, and religion.