Why didn't Napoleon execute Marquis De Sade?

[Esau]

Instead of murdering him, after receiving a signed copy of Justine, he sent him to an insane asylum.

 

[Apochrypha]

Because France is a clown world and always has been.

 

[Table Country]

Given the standards of the time, he might've thought de Sade would like it there.

 

[Pimpleking55]

Napoleon took pity on him, for he thought a man with such a depraved mind could be nothing more than a person who lost his marbles. The French revolutionists however freed him and made him a delegate to the Convention Nationale and France as a nation has gone downhill ever since

 

[Penis Drager]

Because Napoleon wasn't the brutal dictator he is often portrayed as.
He literally brought constitutional monarchy (as opposed to absolute monarchy) to the vast majority of Europe.

Napoleon was a filthy fucking liberal for his time and place.

 

[Those Were the Days]

De Sade utilized his texts to argue philosophically via coital acts and other so called obscenities, disputing various philosophes of the day- Rousseau for instance. Napoléon himself wasn't a classy dude but rather crass so it could simply be that he enjoyed the work in private while having to act appalled in public. He wouldn't be the first person to rise to a high position to be guilty of that...


For anyone interested, the marquis ' Letters from Prison' are rather fascinating...

ETA : Napoléon also brought standardized schools to France, so wherever you go, you can be assured that at least in your formative education, you'll be learning the same thing at roughly the same time.

De Sade escaped being guillotined because the wrong name was read out loud the day before. He was a lucky dude to not perish during the Terror.

 

[Wilhelm Bittrich]

Napoleon was a filthy fucking liberal for his time and place.

Code civil, Code of commerce, Code of criminal procedure, The new criminal code of 1810 (which had no punishments for blasphemy, other religious crimes like witchcraft and homosexuality).
Centralized governemnt administration and introduced the prefecture system
His tax reforms which made taxes simpler and easier to understand for the common man.
Made the French Central Bank provide loans for small businesses.
He laid the base for modern French education.
Abolished the practice of buying a commission into the French Army.
His land reforms and promotion of agricultural science.
Reconciliation between France and the Pope.
Abolished slave trade (March 29th, 1815)

Given his time he was really quite a liberal compared to other Kingdoms like Prussia or even worse Imperial Russia.