I agree that they exist due to each other. If we never knew failure, then that means we would never know what it felt like to succeed. Failure is a lack of success. Failure teaches us lessons and without those lessons the meaning of life would change. Without the two, we would simply exist and I'm not sure what life would be like then. I also think it depends on our definitions of success and failure. Thanks for this thought provoking piece Dr. Neera and for the tag.