Maybe by presenting examples of hidden and public corporate disregard for law in their pursuit of profit. If you don't like the idea of a law as an absolute, maybe the same examples, framed as being against the public good. I want sunion organizers negotiated with, not fired OR murdered. If you're willing to overlook hidden events as "improbable" and public events as "not that bad" I don't really know what would convince such a person.
