If your battle with invaders happens inside your home, then you have only one more misstep before game over. "When asked whether it would be prudent to build a

If your battle with invaders happens inside your home, then you have only one more misstep before game over. "When asked whether it would be prudent to build a defensive wall enclosing the city, Lycurgus answered, "A city is well-fortified which has a wall of men instead of brick." https://en.wikipedia.org/wiki/Laconic_phrase https://en.wikipedia.org/wiki/Laconic_phrase "It is said that if you know your enemies and know yourself, you will not be imperiled in a hundred battles; if you do not know your enemies but do know yourself, you will win one and lose one; if you do not know your enemies nor yourself, you will be imperiled in every single battle." https://en.wikiquote.org/wiki/Sun_Tzu https://en.wikiquote.org/wiki/Sun_Tzu Moral: https://en.wikipedia.org/wiki/Code_signing https://en.wikipedia.org/wiki/Code_signing + https://en.wikipedia.org/wiki/Web_of_trust https://en.wikipedia.org/wiki/Web_of_trust + https://en.wikipedia.org/wiki/Quality_assurance https://en.wikipedia.org/wiki/Quality_assurance