Scientific progress makes moral progress a necessity; for if man's power is increased, the checks that restrain him from abusing it must be strengthened.
Goethe has made a remark upon the perfectability of the human mind, which is full of sagacity: It is always advancing, but in a spiral line.
The evil arising from mental improvement can be corrected only by a still further progress in that very improvement. Either morality is a fable, or the more enlightened we are, the more attached to it we become.