When I was in Spain I visited several museums and tours which talked about all the gruesome torture practices of the Spanish Inquisition.
However, there was a 30-something historian among us and she said she studies Spanish medieval history, and that the multitude of tortured are pop culture inventions. She said that there were simply no credible recordings to support the claims, other than Auto-da-fé and the fact that the prisoners were kept in poor conditions.
I am now reading Sam Harris's The End of Faith where he talks about the Inquisition's tortures as a matter of fact and cites some books. I give more credibility to Sam than the random historian I met, but I still wanted to check whether there's some debate over this.
There are some indications that many stories we know about the Spanish Inquisition, were a part of an anti spanish anti catholic propaganda England and the Netherlands produced in the late 16th century as they were at a war with them at the time and it was the riches country in the world.
The Spanish Inquisition was a national institution, not under the direct control of the Pope so it was easier to attack that institution rather than the Inquisitions directly under the control of the pope .
Monks couldn't shed blood so they had to have some " original" enhanced interrogations, they used usually fear and isolation to get people to recanted their heresy. The wheel was used but no confession that was produced under torture was admissible. If people recanted under torture they would have to recant afterwards as well for it to be admissible. The goal of the Inquisition was to save people from heresy, not burn them, but they were a powerful institution and abused their power, especially towards people of Jewish and Muslim descent
/u/LarperPro
You are right to question assertions made without evidence. I do not know Sam Harris other than he is not a historian so if you are after accuracy, look at his sources or go straight to works of history that cover the Inquisition.
Fortuitously, there is a nice recent thread that should help you get started.