"The risk to be perceived defines the duty to be obeyed." — Benjamin N. Cardozo

History or custom or social utility or some compelling sense of justice or sometimes perhaps a semi-intuitive apprehension of the pervading spirit of our law must come to the rescue of the anxious judge and tell him where to go.

The constant assumption runs throughout the law that the natural and spontaneous evolutions of habit fix the limits of right and wrong.

In law, as in every other branch of knowledge, the truths given by induction tend to form the premises for new deductions. The lawyers and the judges of successive generations do not repeat for themselves the process of verification any more than most of us repeat the demonstrations of the truths of astronomy or physics.

To the question how one kind of labor can be measured against another, how the labor of the artisan can be measured against the labor of the artist, how the labor of the strong can be measured against the labor of the weak, the communists can give no answer.