In almost every country I've heard of, torture was legal and accepted in the early 17th century. I know, for example, that torture was used at the Salem witch trials and against Guy Fawkes. Then I don't know much of anything about the history of torture other than the U.S. banned it with the 8th amendment and by the time you get to the 20th century there seems to have been widespread disapproval of it because countries would use it in their propaganda about each other.
I know torture still is employed in some countries, but that fact that it is at least nominally banned seems almost as great an accomplishment as the abolition of slavery. So who are the William Wilberforces and Frederick Douglases and Harriet Tubmans of the abolition of torture?
Were early bans based more on the idea that torture wasn't a reliable way of getting the truth, or more as torture as a violation of rights?
Cesare Beccaria's 1764 opus, On Crimes and Punishments, contained an impassioned attack on the foundations of torture. Beccaria basically created out of whole cloth the modern criminal justice system, arguing for the protection of the accused, the right to a speedy trial, modern rules of evidence permissibility, etc. After putting forth all these ideas, one of his last arguments is that torture doesn't help in the administration of justice: it is always done to the accused, and rarely produces real confessions, it is non transparent, and so on.
Beccaria's work was really important in the English penal reforms championed by guys like Bentham (I think), who kept On Crimes and Punishments by their side as they worked to effect legal change. Jefferson took quotations of it in his commonplace book, as did the Grand Dukes of Tuscany and Catherine the Great. Obviously not all of it would be followed to the letter (his arguments against the death penalty in particular fell on mostly deaf ears) but Beccaria can be really cited as the first important writer against the cruel treatment of the accused.
Speaking for Germany from 1300 to 1600 (specifically one of the countries oldest cities: Cologne) torture was, even though it was an option and permitted by law, frowned upon. Since a lot of the city councils documents of that period survived and are pretty thorough we have a good idea of how that came to be. Even though Catholic Cologne also was keen on hunting down witches the council and most of the people were very reluctant to carry through punishment (in that case also torture) because it was seen as inhumane and the executioner refused to partake in the whole thing. Punishment at that time was pretty much an eye for an eye. You stole something? Your hand would be chopped off. Killed a peasant? Depending on your status you would be executed. Illegal prostitution? You would be marched to the "Beierlicher" (a public whorehouse, so through your walk of shame you would be stigmatized as a whore for ever). The thing was, if you "over punished" as an executioner you would commit a crime and would also be punished. There are records of the executioner of Cologne being executed, because he messed up decapitating a murderer and made him suffer inhumanly, thus comiting as sin. If you survived an execution you were pardons, because god wanted you to live. If you as a peasant killed a nobleman or even king killing you was not enough, which is why you had to be tortured to death as just taking your life wasn't equal to taking the life of someone with a higher status.
Basically torture doesn't really fit that system because it focuses on bringing suffering and not on doing justice, which is why the executioner of Cologne refuses to partake in such an ordeal. It was very risky and the few times torture was used it didn't yield useful information. This was also documented and influenced the council's decision on further using those practices.
This might be very particular information on that topic, but it's backed by actual documentation from that period.
Source: "Bettler und Gaukler, Henker und Diebe" by Franz Irsigler and Arnold Lassotta
A great book, which sadly only exists in German. It provides a great insight into how the least fortunate people loved through medieval times, a view which is normally underrepresented, as those people tended to be illiterate. It's even greater if you have the opportunity to visit Cologne after reading to see all the places mentioned in the books. A lot of them have been reconstructed or still exist.
All these comments are on Europe. Does anyone know about other regions with different cultural traditions like China or Asia in general?
Another interesting question you might also want to ask, 'Why did (judicial) torture go from being almost completely unknown to the invaders of the Roman Empire to being near universally accepted by the 17th century?'
The earliest example I can think of is the theocratic dictature of Florence between 1494 and 1498. Under the influence of Savonarole, the "Christian and Religious Republic" (with Jesus-Christ himself as ruler) reformed many social and political institutions, including torture that became forbidden.
I can't provide English sources, but there are many in French or Italian.
The ones I used are :
Anna Fontes, Jean-Louis Fournel, Michel Plaisance (dir.), Savonarole. Enjeux, débats, questions. Actes du colloque international (Paris, 25-27 janvier 1996), Paris, Université de la Sorbonne Nouvelle, 1997. (available on Cairn if you have access to the site)
Boutier Jean, Sintomer Yves, « La République de Florence (12e-16e siécle). Enjeux historiques et politiques», Revue française de science politique 6/2014 (Vol. 64) , p. 1055-1081