I think this statement means that when you are doubting something, someone or yourself that it's basically a father figure. Because let's be honest everybody even you and me doubt ourselves or something or someone; Every single day someone out there is doubting/second guessing something, someone or themself. Doubting happens so often that sometimes when you see or hear someone doubting or being doubted you take those actions and doubt on something that you want happen or something about yourself. Lastly I do agree with this idea because if you sit and think about what it might mean it will truly explain a lot.
Northern Italy is more economically successful than Southern Italy and still is today. Cities like Milan, Turin, Genoa, Venice, etc. show economic prosperity in Northern Italy throughout its history.
