I generally see three schools of Judicial thought:
The original intention of the earliest canonical sources RULES. This actually can provide a great deal of activism in the sense that Fundamentalism can lead to a form of REVISIONISM.
In the USA this might read like this: Since the First Amendment NEVER put up a wall between Church and State, and only addressed Congress' ability to establish religion, therefore any law that requires a GREATER separation is either null and void, or at least VOIDABLE.
To stick to canonical documents. To highly restrict revisionism of original intention, in favor of revising laws that fail to conform to fundamentalistic reads of the tomes.
This is based upon the principles of Common Law. The rulings of course are all factored in to make the law. The higher the court the more influential the precedent. Texts and tomes are secondary to how the courts rule in practice. New rulings can introduce new law, but ONLY if other courts ratify this as precedent. Otherwise, Stare Decisis [let the decision stand] is the underlying assumption. Illustration:
In the USA this might read like this: Since Roe vs. Wade is SETTLED LAW, and has even been used as a basis to create other law, the decision stands DESPITE the fact it might have been flawed or not in consonance with fundamental texts.
To create a stable, albeit evolving society, businesses need stability upon which to project their decisions. Property needs protection in order to encourage improvements. Protect values that created the society and to perpetuate these values across generational boundaries.
Since the principles of Liberty and Justice for all are META-LAW, all texts and Traditions may be disregarded in favor of a liberal agenda of maximizing liberty Illustration:
In the USA this might read like this: Since traditional marriage has been restricted for generations to heterosexual couples, we may wish to liberalize these laws and let gays and polygamists have the SAME rights as traditional hetero-marriages. This is in order to spread the most rights to the most people. Fundamental readings of text, as well as history and tradition - take a back seat. They may even have a voice, but not a veto.
To pursue a liberal or a libertarian or a libertine] agenda. To promote progressivism. Maximize rights for the people.
NB: Since I first authored this, I have been informed that there can be more than 3. For Example: "reactionary" - where one would do things OUR way as opposed to the ways of other cultures.
BEH I will stick with these 3 American Models for now. When I do a Jewish parallel, I will add a 4th Jewish/Religious Model.
Kol Tuv / Best Regards, RabbiRichWolpoe@Gmail.com