However many confirming instances there are for a theory, it only takes one counter observation to falsify it: only one black swan is needed to repudiate the theory that all swans are white.

• 不管有多少确实的证明一个理论的证据放在那里，只须一个相反的观察就可以证伪它：反驳所有的天鹅都是白的这个理论只需一个黑天鹅就够了。