Henry David Thoreau Quote

Doubtless, we are as slow to conceive of Paradise as of Heaven, of a perfect natural as of a perfect spiritual world. We see how past ages have loitered and erred. "Is perhaps our generation free from irrationality and error? Have we perhaps reached now the summit of human wisdom, and need no more to look out for mental or physical improvement?" Undoubtedly, we are never so visionary as to be prepared for what the next hour may bring forth.

A Yankee in Canada: With Anti-slavery and Reform Papers (ed. 1866)