Simple.

Let your credo be this: Let the lie come into the world, let it even triumph. But not through me. The simple step of a courageous individual is not to take part in the lie. One word of truth outweighs the world. In keeping silent about evil, in burying it so deep within us that no sign of it appears on the surface, we are implanting it, and it will rise up a thousand fold in the future. When we neither punish nor reproach evildoers, we are not simply protecting their trivial old age, we are thereby ripping the foundations of justice from beneath new generations.

Aleksandr Solzhenitsyn, from The Gulag Archipelago