<span> In Italy and Germany they were elected by the people (albeit in unusual circumstances).
In Spain the nationalists fought a civil war against the elected socialist government. </span>
The correct answer is: "He developed mathematical principles"
René Descartes (1596 – 1650) was a French philosopher, mathematician, and scientist who lived more than 20 years in the Dutch Republic and was one of the main figures of the Dutch Golden Age.
His great influence in mathematics has been his major contribution to the Scientific Revolution, although his work in philosophy is outstanding too. He developed the the Cartesian system of coordinates. He is considered the father of analytical geometry, which connects both algebra and geometry and which has been used in the development of infinitesimal analysis and calculus .
Technology has improved city life in more ways that can be summed up easily. The developments of running water, electricity, sewage systems, public transportation, and many others helped to make city life safer and healthier. In addition technological developments in building construction allowed for taller buildings to be built creating more space for businesses to develop and places for humans to live in cities. In recent decades environmental regulations and cleaner energy use has created healthier and more sustainable living conditions
