If it can prevent someone from going into shock and dying yes, but otherwise no. Invasive surgery is actually really fucked up from an objective point of view. When someone's thorax gets opened up, typically the only prognosis is death. In our genetic history, 99% of the time someone has voluntarally allowed their thorax to be opened up in order to "help them", the person performing the operation was a psycho witch doctor. I imagine that most of the people in our genetic history who did end up getting thorax surgery only did so because they were on lots of narcotics or they were otherwise very out of their right mind. I think it's very reasonable to demand a very high bar of justification from our doctors when they suggest opening up our chest. And it only makes sense that the right way of performing thorax surgery would require quite a lot of conviction on the part of the person getting the surgery. Even from a practical perspective, there are a lot of benefits to being lucid during an important surgery. What better feedback for if the surgeon fucks sonething up than a person who can literally feel it? How many stupid fuck ups like operating on the wrong organ or leaving things inside the patient could be avoided if they weren't knocked out? How many spontaneous decisions have surgeons had to make without the feedback of the person recieving the surgery? If the surgeon is going to be fucking up someone's body anyway then why take a bunch of anesthesia just to fuck up their other organs too? Don't forget that anesthesia is literally a poison. Pain sucks because it's so strongly associated with injury and death. If this thorax surgery is supposedly fighting injury or death, then shouldn't the supposedly informed and consenting patient be able to look past the pain to all of the advantages of the surgery? I actually read an article about someone who had to get open heart surgery with minimal anesthesia because injecting anesthesia in that area was very likely to kill them. It's been done before.