What does this mean? "If all else fails, immortality can always be assured by spectacular error"
This quotation is from the famous economist John Kenneth Galbraith. What it means is that people become just as famous for making huge mistakes as they do for being hugely successful.
I do not know that this is necessarily true, but it is at least close to true. For example, we tend to remember the people who were worst at something almost as much as we remember those who were the best. In sports, many people remember that Sam Bowie was drafted ahead of Michael Jordan and then went on to have a career that was less than amazing. Many baseball fans remember Bill Buckner as the guy who made an error to let the NY Mets win the 1986 World Series or Don Denkinger as the umpire who made a bad call to let the KC Royals win the World Series in 1985 (I think was the year).
So the meaning of the quote is that tremendous mistakes get you to be famous just as tremendous accomplishments do.
My interpretation of the quote is that someone who makes a ciritical mistake will be remembered for that just as someone who is a vital success. We remember those who have done something to one extreme or another. We remember some great people who have done amazing works and we also remember people who were great failures or who had a great failure.
My interpretation: if a person has the opportunity to do something innovative, historical, monumental, etc... that will keep his/her memory alive long after he/she's gone, then that person will take the opportunity to do so in an effort to create a legacy for him/herself. Ex: Alexander the Great
But if a person fails to achieve a high success, a colossal failure will also maintain that the person will be remembered by this means as well creating a sort of immortality in the form of an individual's experience.