this is for entering students who want to know what this mysterious "legal reasoning" thing is all about. it's not, in fact, very mysterious. veterans of law schools just mystify it to boost their own self-esteems. it can be summarized on one leg*, as follows.
1. "issue spotting" is an important part of the process. armed with knowledge of the law, you have to figure out what facts in the fact pattern raise what issues.
2. issues are usually stated as a mixture of factual and legal concepts. e.g. "does Arbuthnot's pocketing the money violate a larceny statute?"
3. once you've identified the issue, you have to apply the law to the facts. sometimes the application is very obvious and straightforward and the conclusion can be neatly deduced. there are very few points on exams for these simple conclusions, and almost everyone gets the points.
4. usually, a general issue has several subparts, each of which must be treated as an issue in itself. e.g. a criminal law issue will require a showing whether a certain action was committed, whether the person who committed the action had a culpable state of mind, and whether the circumstances were appropriate for a conviction. for each of these, the relevant law needs to be stated and applied to the relevant facts.
5. applying the law to the facts usually involves making the best possible case for both sides. there may be two (or more) different legal principles that could in principle apply. in such a case, you apply both to the relevant facts, and show the outcome for each. usually, these will conflict with each other, and you resolve the issue by arguing that one principle should apply rather than the other - possibly for general philosophical reasons, but preferably because it's more pertinent to the issue at hand.
6. other times there's just one legal principle, but the facts don't straightforwardly support a conclusion. this can be because the facts are a mixture of those that support a conclusion and those that support a different conclusion; or it can be because there are some facts that favor a conclusion, but there are possibly not enough, or they are not strong enough, to meet a burden of proof. again, you argue both sides.
and that's just about it. if you found this post useful, you should buy me a drink. i'm at la luna cafe in central square, cambridge, MA right now. if you read this at some future time, shoot me an e-mail to find out where i am. if i'm dead, just pour the drink over my grave. peace.
* this is an anglicization of a useful hebrew idiom referring to a quick summary; the idea being, you do the summary while the other person stands on one leg. there's an old shamai and hillel story about it.