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)
“To walk through the ruined cities of Germany is to feel an actual doubt about the continuity of civilization.”
—George Orwell (1903–1950)