It is better to remain silent and be thought a fool that to speak and remove all doubt

It is better to remain silent and be thought a fool than to speak and remove all doubt is a line that was originally spoken by Abraham Lincoln and has since become a very common phrase and quote. The phrase means that if you are silent, people dont know if you are a fool or not because you have not said anything, but if you speak you may sound like a fool and they will not doubt how foolish you are.