Given the increasing numbers, scope and complexity of laws, is it humanly possible for a single individual to read each one start to finish in the course of a professional lifetime?

It is an ancient principle that ignorance of the law is no defense. But this principle originated in times when laws were few and widely known and understood.

Surely we are approaching, or perhaps beyond, the point at which the sheer volume of legislation makes ignorance a reasonable defense, or at least a mitigating factor, so long as a good faith effort to generally act in a legal manner can be demonstrated.