原版英文："The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts."
- ↑ Burson, Katherine A.; Larrick, Richard P.; Klayman, Joshua (2006). "Skilled or unskilled, but still unaware of it: How perceptions of difficulty drive miscalibration in relative comparisons". Journal of Personality and Social Psychology. American Psychological Association. 90 (1): 60–77.
- ↑ Bertrand Russell Quotes. BrainyQuote.
- ↑ QUOTATION CELEBRATION.
- ↑ BookBrowse's Favorite Quotes.