One of the rules of the Roman Republic was that the laws should be publicly visible, so all could read them and there was thus no reason that one would be ignorant of them. This is predated by the commands Joshua obeyed here.
30Then Joshua built on Mount Ebal an altar to the LORD, the God of Israel, 31just as Moses the servant of the LORD had commanded the Israelites, as it is written in the book of the law of Moses, “an altar of unhewn stones, on which no iron tool has been used”; and they offered on it burnt-offerings to the LORD, and sacrificed offerings of well-being. 32And there, in the presence of the Israelites, Joshua wrote on the stones a copy of the law of Moses, which he had written. 33All Israel, alien as well as citizen, with their elders and officers and their judges, stood on opposite sides of the ark in front of the levitical priests who carried the ark of the covenant of the LORD, half of them in front of Mount Gerizim and half of them in front of Mount Ebal, as Moses the servant of the LORD had commanded at the first, that they should bless the people of Israel.34And afterwards he read all the words of the law, blessings and curses, according to all that is written in the book of the law. 35There was not a word of all that Moses commanded that Joshua did not read before all the assembly of Israel, and the women, and the little ones, and the aliens who resided among them
Now the entire Law, the Torah, contains some 700 odd commands. The meaning and reasoning behind them have occupied the minds of scholars and rabbis for millenia. But there are only 700 commands. Contrast this with our modern laws — I think the recent health act in the USA — “Obamacare” — runs to some 2000 pages. I do not think anyone understands it, and no one understands US tax law. The very complesity of the law, and the penalties applied, make felons of people who should be citizens.
And this does not have to happen. Tax law in NZ is complex, but fairly simple — we have lower tax rates because we have removed almost all tax breaks (there is one for charitable donations, and that is about it) and we use indirect taxes such as GST (VAT) — again at one rate, no exceptions. This allows people to understand what they need to do, withoug having to hire a tax lawyer in addition to their accountant.
We forget that the Law was fairly simple. And we have difficulty keeping that.
The baroque complexity of modern laws are such that almost everyone will break them. And that is not law. That subverts law, and leads to either anarchy, gangster politics (as in Chicago) or tyranny.