Jane Jacobs (04.05.1916 - 25.04.2006)

Jacobs had no professional training in the field of city planning, nor did she hold the title of planner. She instead relied on her observations and common sense to illustrate why certain places work, and what can be done to improve those that do not. Together with William H. Whyte, Jacobs led the way in advocating for a place-based, community-centered approach to urban planning, decades before such approaches were considered sensible.
"Jane Jacobs' observations about the way cities work and don’t work… revolutionized the urban planning profession. Thanks to Jacobs, ideas once considered lunatic, such as mixed-use development, short blocks, and dense concentrations of people working and living downtown, are now taken for granted." -- Adele Freedman, The Globe and Mail
in http://www.pps.org/info/placemakingtools/placemakers/jjacobs e
http://en.wikipedia.org/wiki/Jane_Jacobs