But, like the owner of a foul disease,
To keep it from divulging, let it feed
Even on the pith of Life.

– William Shakespeare

Hamlet, Act 4, Scene 1. Claudius describes Hamlet’s madness as a foul disease that he neglected to deal with. Because he didn’t want to admit that Hamlet was mad, Claudius says that he did nothing about it, and so the problem grew worse.