Social progress takes effect through the replacement of all institutions by new ones; and since every institution involves the recognition of the duty of conforming to it, progress must involve the repudiation of an established duty at every step.
It is curious to note the old sea-margins of human thought! Each subsiding century reveals some new mystery; we build where monsters used to hide themselves.
Science has given to this generation the means of unlimited disaster or of unlimited progress. There will remain the greater task of directing knowledge lastingly towards the purpose of peace and human good.