Famous quotes containing the words single and/or observation:
“We saw many straggling white pines, commonly unsound trees, which had therefore been skipped by the choppers; these were the largest trees we saw; and we occasionally passed a small wood in which this was the prevailing tree; but I did not notice nearly so many of these trees as I can see in a single walk in Concord.”
—Henry David Thoreau (1817–1862)
“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)