I don't think I would be able to commit murder. Although if someone threatened me I don't think I would think twice defending myself even if it meant killing the person. I have only been faced with this once and I didn't kill the person only hurt him really bad. I was in college and while I was walking back from a friends dorm a guy came behind me and held a knife to my throat. I turned it on him, and took him to the ground. The cops had to arrest him in the hospital. I grew up in my dads Filipino martial arts dojo and I had practiced knife fighting since I was 5. I guess he was in the wrong place at the wrong time.