There is no 'necessary connection' between what is legal and what is moral. [=what is legal does not always have to be moral and what is moral does not always have to be legal]
Higher prices are a 'necessary consequence' of the company's new services.
I'll 'do the necessary' [=do whatever is necessary] to get the job done.
(..) All right then. Now stop your crying and smile. You can take Prissy with you. Start packing Miss Scarlett's things, Mammy. I'll go write the necessary letters. Atlanta! Savannah would be better for you. You'd just get in trouble in Atlanta. What trouble are you talking about? (..)1939 Gone with the Wind