What exactly does Yoda mean when he says this? Is he telling Sidious to not be so confident in the sith? Does yoda mean that even though the darkside can make you stronger, but you lose your humanity and therefore most of your judgement and become weaker? Or does Yoda secretly know whats about to happen to Vader? I assumed he meant it because Yoda was still under the impression that He and Obi Wan were still capable of defeating the sith and that he assumed Vader would be killed? Or did he just mean that the lightside always conquers the darkside. Opinionate!