Lewis Mumford, a philosopher, planner, critic and educator who warned of the dehumanizing effect of technology, died in his spartan, functional country home. He was 94. He died on Friday ``of old age'' in his sleep, said his grandson, James Morss. ``He was frail, but there was no sickness.'' Mumford, best known for his writings on cities, culture and architecture, authored more than 30 books, including ``The City in History,'' for which he received the 1961 National Book Award. He was awarded the National Medal of Arts by President Reagan in 1986. Recipients are honored for their lifetime contributions to American arts. The roots of Mumford's philosophy grew from the America of a century ago. He embraced the notion of self-reliance put forth by Whitman and Emerson. He also was inspired by Melville and Thoreau, who stressed the virtues of humanism and a personalized society. ``The test of maturity, for nations as well as individuals, is not the increase in power,'' he said near the end of his life, ``but the increase of self-understanding, self-control, self-direction and self-transcendence. For in a mature society, man himself, and not his machines or his organizations, is the chief work of art.'' Mumford urged people to turn away from faceless technology and return to human feelings and moral values. He vehemently denied accusations that he saw science as evil and wanted to destroy machinery with the hope of bringing back a pre-industrial society. What he feared, he said, was science without conscience and ``a dominant minority'' of those people who had mastered high technology holding power over others as a result. The illegitimate son of a businessman, Mumford was born in New York City on Oct. 19, 1895, and grew up on Manhattan's West Side. He attended night classes at City College for five years, but failing health prevented him from completing his degree. Instead, he took graduate courses at Columbia University and at the New School for Social Research. It was then he discovered the works of Sir Patrick Geddes, a Scottish town planner whose influence he called the most important in his life. After serving as a naval radio technician in World War I, Mumford became associate editor of The Dial magazine. His essays on housing and urban matters led him to become acting editor of The Sociological Review. Mumford was co-founder of the Regional Planning Association of America and served on the staff of the New York Housing and Regional Planning Commission. In the 1930s, he began weekly art columns and monthly architecture critiques for The New Yorker. From 1934 to 1951, he published four books that became known as the ``Renewal of Life'' series. They made his international reputation and landed him on Time magazine's cover. The volumes _ ``Technics and Civilization,'' ``The Culture of Cities,'' ``The Condition of Man,'' and the ``Conduct of Life'' _ established Mumford as a first-rate thinker. Visiting professorships at MIT, Dartmouth, Stanford and the University of Pennsylvania followed. Among honors bestowed upon him were the President's Medal of Freedom in 1964, the Gold Medal of the Town Planning Institute, the Emerson-Thoreau Medal of the American Academy of Arts and Sciences, the Leonardo da Vinci Medal of the Society for the History of Technology and an honorary knighthood of the Order of the British Empire. He is survived by his wife, Sophia; his daughter, Alison Mumford Morss, and two grandchildren, James and Elizabeth.