This enlightenment hundreds of years ago is more true today than ever. The internet and social media have become weapons not just of extremists such as Isis, but for anyone who wants to publicly shame and humiliate others.
The irony is that sometimes on social media, we become our own weapons of mass destruction.
Like Napier woman Karen Hammond, who baked a fruit and chocolate cake, then painstakingly iced it with a reference to her former employer in pink icing.
Not your run-of-the-mill iced nicities but instead a couple of foul-mouthed references to Credit Union Baywide. The frosty dessert was enjoyed by Hammond and a group of friends at a private dinner party.
The joke - as presumably it was intended to be a joke, albeit a rather crude one - might have ended there.
But an image was uploaded to social media, and then into the hands of New Zealand Credit Union executives. It might also have ended there but the image was then distributed to recruitment agencies and Hammond's new employer with a request that she be sacked.
This week Hammond was awarded more than $168,000 in damages for breach of privacy and "humiliation, loss of dignity and injury to feelings", following a Human Rights Tribunal hearing late last year.
With the ruling came a flurry of opinion on the internet. The cake, meant for 10 people, has now been shared by millions.
Public opinion seemed divided on the issue of whether justice was served. Or, as one pundit put it this week, was it a case of sweet revenge or a slice too far?
Two website posters on NZME. websites sum up the different stances. On the one hand people felt the amount was ludicrous, and that Hammond was in the wrong for making the cake in the first case.
Poster Don Henderson says, "We continually read of these cases where justice is turned upside down to favour every employee who breaches trust, rips off his employers and a lot of other nasties. They are actually rewarded handsomely for being lazy, dishonest, treacherous, abusive and so on to their employers. Who would be a boss in this country!!"
Others felt this was a victory for the employee against the big employer. Jim Martin posted, "I support this decision. Nothing that happens outside of the workplace is any of their business. Our employers are not our parents or our owners. A company attempting to restrict freedom of speech in social settings is frighteningly Orwellian."
Like Martin, one could argue that what Hammond did in her own time was her own business. Her cake, though puerile, was intended presumably as a fun thing to share with friends.
One could also argue that even though she did post it to Facebook, it was intended to be seen just by her friends. The company executive who distributed it acted deliberately to sabotage Hammond's future career.
But you could also argue that when the cake was posted to social media, the notion of privacy is lost. Plus icing the cake in such a way was not a momentary lapse of judgment but a deliberate act.
While many people might relate to moaning about their employers with friends, it seems extreme - bizarre even - to go to the effort of calling them certain names starting with 'c' in pink iced letters.
What sort of person does that one might ask? Does it matter what sort of person they are?
It does actually to a potential employer.
But that is not a reason for their former employer to spread news of their actions.
It seems to me that both were in the wrong. But legally it is the employer who has breached privacy.
The size of the payment seems deserved when considered how difficult the actions of the former employer would have made it for Hammond to get good jobs in the future.
As for loss of dignity, in my view Hammond lost that herself when she made the cake in the first place. Unfortunately in the days of social media we are not allowed to live down or forget our mistakes and lapses of judgment but they can be paraded for all to see.
You cannot expect freedom of expression on one hand, in the icing of the cake and putting it online, and then expect complete privacy on the other.
Although in this case the tribunal ruled in Hammond's favour, it is a lesson for employees and employers. You can't have your cake and eat it too.