U.S. law is primarily based on a combination of judicial, legislative, and constitutional structures that effectively prescribe rules for ordering the formal and prescriptive aspects of society. These structures are spread over three layers: federal, state, local.

The federal constitution defines the broadest formal structure to which all the rest must conform: it defines what powers and limitations apply to the national government (consisting of three co-equal branches) and leaves scope for state and local governments to function within their own realms of sovereignty and to define the rules by which they do so. In theory, federal sovereignty is strictly limited and any powers not expressly given to the federal authority by the constitution are reserved to the states. Within the scope of its express powers, the federal authority can but need not preempt all state and local law. States in turn have their own constitutions and these provide that state law can but need not preempt local laws. Where laws are not preempted, they can peacefully co-exist in a way that, in the aggregate, defines the broad scope of the American law as a whole.

Within this broad framework, you have the legislative, the judiciary, and the executive functions (again, existing in separate forms at the federal, state, and local levels). The legislature enacts statutes that set forth formal rules governing this or that in society, taken as a class. Courts decide particular cases and controversies and publish decisions that in turn can become binding law as precedents commensurate with the scope of authority vested in the court deciding the case (with decisions of the highest courts, e.g., the U.S. Supreme Court, having potential binding effect on the entire nation and with decisions of other appellate courts, both federal and state, having important but more restricted binding effect) and also interpret the meaning of legislative enactments as disputes arise as to their particular meaning in a given case or controversy. Legislative enactments can also set up administrative agencies that have full authority to administer a particular statutory scheme (e.g., the Federal Communications Act sets up the F.C.C., which has plenary authority to determine how the statutory scheme is implemented as defined by what Congress intended in enacting the statute).

To be a good U.S. lawyer, you need to be well educated and trained to function within this system. This means having a good logical mind that is able to understand and sort through the various formal systems and layers of law, to understand what they each mean, to understand how they relate to each other, and (most important) to discern how all of these apply to and affect any particular case (either in structuring a transaction or fighting a dispute). This, by the way, is why it is so difficult and even potentially treacherous for those who have not been so trained to read a few "rules" and just assume they know what they are doing in concluding that, because of this or that rule, this or that must follow. That approach can work well for many situations but can get you into big trouble if you are missing key pieces that might also apply to the particular situation and that you simply do not see (or do not appreciate the effect of). This is also why law has been so stubbornly resistant to the idea of being reduced to algorithmic solutions along engineering lines. Law certainly does have its patterns and can be reduced to algorithmic solutions in discrete areas but trying to do so across the spectrum of the different layers of sovereignty, the spectrum of legislative enactments and judicial decisions, and byzantine areas of administrative law (e.g., U.S. Tax Code regulations) is a difficult task of a very tall order.

In my day at law school (late 1970s - and I believe it is broadly similar today), American law schools primarily used the "case system" as the preferred approach to teaching students to learn to "think like a lawyer." In other words, you learned very little about the actual day-to-day practice of law but you studied intensely to learn all the formal structures and to read through, analyze, and master appellate level case law interpreting and applying that law in the form of particular cases and controversies. As a given important case would be decided, you would learn the legal principles it expounded, whether it was about tort law, contract law, real property law, criminal law, or whatever.

Back in that day, law schools would also offer limited offerings focusing on a few important legislative schemes and also giving very limited opportunities to do short internships giving some practical experience.

In general, what all this meant was that good law school graduates would master the formal aspects of the law and would be let loose into the real world knowing very little about how any of it actually worked.

Once you passed the bar exam and began actual real-world practice, it would typically take a full year or two before you could anything that resembled efficient practice, another couple of years before you learned to handle relatively simple things both competently and efficiently, and another several years before you could learn to do all of the above and, in addition, learn to think strategically. When you can finally do all of this, you are functioning at partner level.

In essence, then, all that I have described in the immediately preceding paragraph, is effectively a true apprenticeship. And this is a huge part of becoming a good lawyer.

Can you skip the formal education and still become a good or even a great lawyer? Absolutely. Is it easy to do? No, it is very difficult and that is the advantage of the formal education via law school. In essence, what you are buying through a good law education is (one hopes) expert guidance through a complicated thicket. It helps you focus and also learn through lectures what academics can teach about the fascination of legal logic. This does not always work well but, in really good law school, it does and it helps a lot. Is it indispensable? Not at all. There are many gifted people who have the right aptitude and can bypass the formal education without any detriment whatever. If they are properly apprenticed, they can learn all that is necessary in a real-world environment and supplement this with independent study. Strong auto-didactic skills are very much needed here. But with that, and a good mentor, you can master the practice of law without problem. After all, the vast bulk of what most formally educated lawyers learn is also through the apprenticeship part of their training. So, in important ways, the different paths do overlap.

Is it easy to market what you do having gone the pure apprenticeship route? I would say that, here as well, there are significant difficulties. It can be done but likely only if you are good enough to make a mark with clients while serving as an apprentice and thereby building a reputation such that clients will overlook the lack of a formal law school education. This works better in specialty fields than in others.

Am I saying the law school approach is better? It probably is and it certainly is a lot easier. But I am all for the apprenticeship approach for those who have the skill and the aptitude. There is enough of the guild system built into American legal systems and anything that gives people more choices is to be welcomed.