Permissive will?
I think God distinguished between what is moral and what is workable AS CIVIL LAW. For example, if there was a 100% ban on divorce, would women be more likely to be murdered? Or would men be less likely to take wives and more likely to have concubines?
What is right for believers to do may be different from what is best for all concerned in a society that has many unbelievers.
Civil law needs to concern itself with society while moral law is about the individual. And our society, if pushed to ban ALL abortions, may turn around and allow UNLIMITED abortions.