Famous quotes containing the words principal and/or cities:
“There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.”
—Denis Diderot (1713–1784)
“The city is always recruited from the country. The men in cities who are the centres of energy, the driving-wheels of trade, politics or practical arts, and the women of beauty and genius, are the children or grandchildren of farmers, and are spending the energies which their fathers’ hardy, silent life accumulated in frosty furrows in poverty, necessity and darkness.”
—Ralph Waldo Emerson (1803–1882)