影片筆記 Crash Course - Rethinking Civilization

Barbarians: 化外之民，或稱野蠻人？

Civilization，都市化，是從原始社會進化到部落社會的過程
Agriculture與Food Surplus是形成氏族社會的最重要環節。只有確定Food Surplus，剩餘人力才有機會從事其他工作，創造文明，Army ... So on and so forth
And that's why the top 3 biggest ancient Civil Society all located along rivers.