The son of Philip and Frances Ankenbrand Defliese was born February 11, 1915, in Queens County, New York City. He attended Bushwick High School in Brooklyn, New York, graduating in 1931. After graduation from high school he accepted a job with New York Title & Mortgage Company (NYT&M) and attended the City College of New York in the evenings receiving a bachelor's degree (cum laude) in 1938, with a double major in accounting and education.
He was promoted to the accounting department at NYT&M; however, he left the firm in 1938 to become a full-time "permanent substitute" accounting teacher under Mayor LaGuardia at Grover Cleveland High School in New York City where he taught for four years. During this period, he continued to attend evening classes at the City College of New York, receiving his master's degree in 1940 in business education. He completed all but his dissertation for his doctorate degree at New York University. In 1975, an honorary Doctor of Commercial Science degree was bestowed upon him by Villanova University. He was certified as a CPA in 1947.
In 1942 he joined Coopers and Lybrand. About a year later he left the firm to serve (1942-46) in World War II. In 1942, he entered the U.S. Navy as a midshipman under the V-7 program at the University of Notre Dame. He was commissioned an ensign, with specialization in anti-submarine warfare; he later served three years of sea duty in the Pacific and Alaska. After receiving an honorable discharge as a lieutenant, he spent the next year (1947-48) as an assistant professor at Adelphi University before returning to Coopers & Lybrand in 1948. He became a partner in the firm in 1956 and he served as the firm's national director of accounting, auditing and SEC services during the period 1962-68. He was the managing partner and chairman of the executive committee of the firm from 1968 through 1976. After meeting Coopers and Lybrand's mandatory retirement age in 1977, he joined the accounting faculty at Columbia University where, after eleven years he is now professor emeritus. He has also taught as an adjunct professor at Pace University (1950-56).
He has been active in professional organizations. He served on a number of AICPA committees including being a member of the Practice Review Committee (1962- 65), the Committee on Relations with Bankers and other Credit Executives (1965-69), and chairman of the Committee on Specialized Audits (1960-62). He was also a member and chairman of the Committee on Auditing Procedure (member 1957-59; chairman 1959-62). He was a member of the AICPA Council; first as an elected member from New York (1964-67) and then as a member at large (1969-74). He served as chairman of the AICPA's Board of Directors during the period 1974-75. For nine years he was a member of the APB (1964-72) including three years (1970-72) as the last APB chairman. He was a member of the advisory council of the FASB for a year and a half (1973-74) and he has been a member of the GASB since its formation in 1984. He served as a member of the New York State Board of CPA Examiners (1964-69) and as the first chairman of the New York City Audit Committee (1979-84). He currently serves as a director of several companies and he served as a consultant to the U. S. Defense Department. For his distinguished service to the profession, he was awarded the AICPA's Gold Medal Award in 1972. He is a member of Beta Alpha Psi, Beta Gamma Sigma, and Delta Psi Epsilon.
He is co-author of four editions (8th-11th), including the first college version (which was started with the 10th edition) of Montgomery's Auditing, first authored in 1912 by Hall of Fame member Robert H. Montgomery. He has also contributed over 50 articles to professional journals.
He married Pauline Harnisch on April 28, 1946; they have three children. His hobbies include sailing, hiking, water skiing, and golfing. His interest in the Boy Scouts continues from his days as an eagle scout and an award-winning scoutmaster.