Inability to tell good from evil is the greatest worry of man's life.
This quote is often attributed to Cicero. Unfortunately, I'm struggling to find much on Google beyond various "inspirational quotes" sites repeating the same basic info: the quote, and the speaker. A Google snippet shows partial info, but after looking, it seems like that is actually a reference to some other material.
I'd like to confirm that this was, in fact, a quote from Cicero and take a look at the original statement in the original context if I can. Does anyone know of the source for this quote?