The analysis/synthesis method outlined above is applicable to all determinations of whether there is a violation of the law, or whether there is a violation of a duty under contract or a tort, giving rise to a claim. However, it is wholly inapplicable in connection with arguments about what the law should be.
In fact, the greatest single revolution in legal research in the last 50 years has been the development of the field of law and economics, bringing social scientific methodologies to bear on policy questions about the law. This study asks questions about the empirical results of legal rules, as well as asking how legal rules come to be made. Law schools have increasingly recognized that the traditional disciplinary tools of law can be greatly enhanced by incorporating other social scientific disciplines when the goal is to create or evaluate public policy.
The field of law provides no insight into whether there should be a minimum wage, whether capital gains should be taxed at a lower rate, whether capital punishment is a good idea, or how long a prison sentence should be. Economists, philosophers, sociologists, and other experts have better tools to respond to these types of questions.
Nevertheless, in the U.S., and in many other countries, lawyers have a leading role in government, including in legislation and regulation. And experienced lawyers can indeed be helpful in evaluating the mechanics of a particular law. For example, they can evaluate whether courts or other decision-makers will be able to determine the different components accurately or not, or whether a rule can be applied consistently.