Are there books or sources on how laws are evolving in a way that current laws have little to do with original purposes?

Question

I am seeing pattern where laws that used to serve some purposes is now serving very different purposes. I wonder if there is a name for these patterns.

According to

Why are there distinct burdens of proof in civil and criminal cases?

Beyond reasonable doubt are there to protect jury. Juries at that time fear that they will go to hell if they convict an innocent man. So the rule is made that the jury must conclude that the defendant is guilty beyond reasonable doubt.

Of course, the purpose and the meaning is no longer there. The purpose of beyond reasonable doubt cases is now a way to protect defendants.

That's because, of course, values have changed.

US have become secular countries. Yada yada.

Statutory rapes laws also evolved.

https://digitalcommons.law.utulsa.edu/cgi/viewcontent.cgi?referer=https://law.stackexchange.com/&httpsredir=1&article=1080&context=fac_pub

It says that statutory rapes laws are there to protect virginity of young girls.

That would make a lot of sense.

Virginity was very important at that time.

Virginity of boys are "worthless" and hence not worth protecting. So a hot beautiful young teacher having sex with young boy would be "nice".

However, as times go buy, we have men and women treated equally.

Also marital age have gone up and virginity is not important anymore.

So now, statutory rapes would actually protect a 15 years old boy that rape an 21 years old girl. That 21 years old girl will have strong incentive not to report the rape due to statutory rapes law.

When an adult is raped by a juvenile, the offense of statutory rape imposes criminal liability on the adult for the same intercourse by which the adult is a victim of rape. In this way, the offense of statutory rape criminalizes being raped; it criminalizes being the victim of rape. It criminalizes the failure to prevent or resist being raped by a juvenile. And neither defenses specific to statutory rape nor defenses of general application satisfactorily preclude liability.

If an adult is raped by a minor, is it statutory rape?

Another sample I can think off is adultery laws. Before paternity tests, adultery means paternity frauds. Men with power and wealth will end up inheriting his wealth to someone else' child if his wife commit adultery.

Times changed.

We can just use paternity tests to know who the father of the child is. So adultery laws become meaningless. In most states it's legal. Being legal, getting married no longer protect men from paternity fraud. If anything, getting married expose men to more liability of paternity fraud.

Are these "evolving idea", or phenomena, where a rule makes a lot of sense a long time ago, but somehow have been very different now have a name? So the laws were there for a reasonable purpose. And now the law is there for totally different purpose.

What are these called?

Answer 1

Books on the history of law, and on legal theory, are particularly likely to explore this issue.

Some related concepts are "legal realism" which looked beyond the formal justifications for laws to more fundamental motivations that drive how they are enforced, "critical theory" which is also skeptical of the formal justifications for laws but tends to focus on Marxist and identity politics justifications (e.g. to explain differences in the treatment of chemically identical crack cocaine and powder cocaine offenses), and "structural functionalism" in sociology, which emphasizes how social structures are driven by functional demands placed upon them.

The doctrine of stare decisis is the overarching principle of how case law molds the law in response to changing conditions, and scholarship related to this doctrine will often implicate how the law changes in emphasis or meaning over time in response to changing conditions.

Answer 2

Yes - any general law book will deal with this

In common law systems, judges apply the law to the particular facts of the case. The law means the statutes passed by the legislature, regulations properly made by the executive and precedent set by other judges in higher courts in the particular appellate chain.

Within the constraint of those laws the judge may need to create or alter a law to fit the specific case, including the changed society that the case exists in. Now, lower courts are bound by precedent, even if that precedent was set in the 1700s - indeed there are plenty of judgments where the judge says "I don't agree with agree with it but Lord Farquart said in Some Guy v Some Other Guy [1856] ...". These judgments often get appealed up to a court that is not bound by the precedent who can then set a new precedent. Alternatively, these sorts of cases can serve as notice to the legislature who may enact a law that overturns the old law.

For example, in Obergefell v. Hodges, 576 U.S. (2015) the Supreme Court of the United States ruled that the fundamental right to marry is guaranteed to same-sex couples by both the Due Process Clause and the Equal Protection Clause of the Fourteenth Amendment to the United States Constitution. It is unlikely that this interpretation would have been contemplated by any of the people who drafted it and passed it in the 1860s - even the ones who were in same-sex relationships. Legislative intention is one thing the courts consider, however, it is not the only thing - they also consider what the law actually says and what that means within current society.

This is basic jurisprudence and is covered in the opening chapter of any first-year law text.