Via Justin Taylor, Martin Luther King on December 18, 1963:
Now the other myth that gets around is the idea that legislation cannot really solve the problem and that it has no great role to play in this period of social change because you’ve got to change the heart and you can’t change the heart through legislation. You can’t legislate morals. The job must be done through education and religion.Speech Transcription - Dr. Martin Luther King's 1963 WMU Speech Found - Archives - WMU Libraries
Well, there’s half-truth involved here.
Certainly, if the problem is to be solved then in the final sense, hearts must be changed. Religion and education must play a great role in changing the heart.
But we must go on to say that while it may be true that morality cannot be legislated, behavior can be regulated.
It may be true that the law cannot change the heart but it can restrain the heartless.
It may be true that the law cannot make a man love me but it can keep him from lynching me and I think that is pretty important, also.