Ethics change with technology.
Moral codes adjust themselves to environmental conditions.
A crime persevered in a thousand centuries ceases to be a crime, and becomes a virtue. This is the law of custom, and custom supersedes all other forms of law.
Samuel Langhorne Clemens, 1835-1910
What humanity abhors, custom reconciles and recommends to us.
We are like chameleons, we take our hue and the color of our moral character, from those who are around us.
The highest ethical duty is often to discard the outmoded ethics of the past.
Should our moral beliefs really prove to be dependent on factual assumptions shown to be incorrect, it would be hardly moral to defend them by refusing to acknowledge the facts.
Today it is not nearly enough to be a saint, but we must have the saintliness demanded by the present moment, a new saintliness, itself also without precedent.