I recently wrote an article for Torah Musings that focuses on a part of the answer that hasn't been focused on yet. "What does Mesorah Mean?" http://www.torahmusings.com/2015/08/what-does-masorah-mean . To quote just enough to capture the thesis, although it omits much of the argument and R JB Soloveitchik's poetry:
We speak of someone “having a masorah” in two ways: both if they have a received practice and cultural tradition (as above) and if they have a known rebbe-talmid lineage. In both contexts, we’re talking about the importance of all that Torah that doesn’t fit into books.
We talk about a hands-on Jewish professional–such as a sofer, mohel, shocheit, etc.–also of “having a masorah” from the one who taught him the craft. Here too we are speaking of the kind of knowledge you need to learn with your senses and muscles, and not know from books discussing the topic in the abstract.
To pasken mar’os, a rav must also have a masorah on how to determine colors. It’s a skill, a craft, that is learned from practice under the guidance of a mentor. This training, the acquisition of a “masorah,” is usually called “shimush.”
For regular pesak too there is an element that is a craft, an art, a skill, the kind of thing one needs to learn from shimush, not by studying from texts.
Kara veshanah velo shimeish talmid chacham, harei zeh am ha’aretz…. If
he read scripture and studied law, but did not serve a talmid chacham,
such a person is an am haaretz (an ignorant peasant).
– Sotah 22a
This is why I like R. Dr. Moshe Koppel’s metaphor of laws of grammar for some usages rather than always comparing halakhah to civil law. The “First Language” model is much like Dr. Haym Soloveitchik’s mimeticism, but with key differences. Halachic rules are an approximation of something that is inherently more complex in kind than rules and algorithms. This is similar to the way grammar is only approximated by ever more complex rules which still never get a foreigner studying the language in class to the same feel for grammar that the native-speaker has. (And why the Oral Torah loses something when not actually kept oral.) So the English as a Second Language student may know what a past pluperfect is, and I don’t, but the native speaker is more likely to know what is valid poetic license and what will produce non-English results.
Similarly, a poseik needs to pick up that feel, and not only the formal rules. He needs the unstructured knowledge of halakhah.
You can’t pasken from codes, from legal knowledge. It takes knowledge of how the codes reached their conclusion – both textual knowledge obtained from commentaries, and the skill to pasken. The latter is obtained with shimush.
Mimeticism transmits the values we were given at Sinai. Without a deep connection to the Sinai culture, we can never be sure whether our rulings are driven by Torah values, natural morality, or a moral code absorbed from the surrounding society.
Advances in technology and developments in society can cause changes in practice. Such changes can alter the circumstances in some subtle way such that the previous ruling does not apply, both in physical ways and in subtle changes in the people about whom the poseik is ruling. And so the Rav questioned the appropriateness of reciting a blessing on Shabbos candles when the electric lights are already on. Similarly, he ruled in the 1950s that a woman aiming for a bachelor’s or higher degree was in a different enough situation for precedent rulings about teaching gemara to females not to apply.
Without masorah, the poseik has no way of determining which solutions to new problems are in concert with the spirit of previous rulings. Halakhah is not frozen; it does not have inertia, but it does have momentum. Apprenticeship, training under a master, transmits the feel for where the halakhah has historically been taken. Following reasoning found in a minority ruling is appropriate only when one is motivated by the Torah’s own principles. The person who speaks halakhah as a first language knows when an innovative change is within “poetic license”, and when the result simply violates the Torah’s “grammar.”
As R. Yochanan quotes in the name of Rabbi Shimon bar Yochai, “gedolah shimushah shel Torah yoseir meilimudah – the apprenticeship of Torah is greater than its study”. (Berakhos 7b)