Plato on why friendship between bad people is not possible

“‘Have you come across the writings of our wisest men, which say that like must always be friend to like? These are, of course, the men who discuss and write about nature and the universe.’

‘That’s true,’ he said.

‘Well,’ I said, ‘are they right?’

‘Possibly,’ he replied. …

[But] ‘We think that the closer one wicked man gets to another wicked man and the more he associates with him, the more he becomes hated by him, because he wrongs him; and it is, of course, impossible for wronger and wronged to be...