Taxes are not good things, but if you want services, somebody's got to pay for them so they're a necessary evil.

Work is a necessary evil to be avoided.

Politics is a necessary evil, or a necessary annoyance, a necessary conundrum.

It may be necessary temporarily to accept a lesser evil, but one must never label a necessary evil as good.

The world is the best of all possible worlds, and everything in it is a necessary evil.

Government is an evil; it is only the thoughtlessness and vices of men that make it a necessary evil. When all men are good and wise, government will of itself decay.