And the answer seems to be that such laws are made in times when morality has fallen into decay, and there are no principles, and therefore injustice abounds.
For in the absence of any moral principles, how are people to decide what is right and wrong? A set of principles of some sort allows people to measure the virtue of their actions. Just like a ruler allows them to measure the length of things, or a set of scales allows them to measure the weight of things.
In the absence of a guiding set of principles, nobody knows the good or evil of their actions, just like in the absence of a set of scales nobody knows the weight of anything.
It's like going into a greengrocer and asking for a pound of potatoes, and the grocer hands you a single small potato, and you say: 'Is that really a pound of potatoes?' And he says, 'Well, that's what everybody thinks a pound of potatoes is.' And you ask, 'Haven't you got some scales to measure it with?' And he says, 'Scales? What are they?' And he says, 'Listen, you're obviously new around here. And round here a pound of potatoes is whatever anybody thinks a pound of potatoes is. It's the consensus opinion.' He calls over one of the other customers and holds up the small potato and says, 'Is this a pound of potatoes, in your view?' And the other customer says, 'It's pretty darn near a pound of potatoes. Perhaps a bit under.' And the grocer turns to you and says, 'See! He thinks it's a pound of potatoes. And I bet you that any other customer of mine would agree it was too. Now do you want this pound of potatoes or don't you?' And you can't argue any more, and anyway you're hungry, so you nod your head. And the grocer puts the little potato in a little paper bag, and hands it to you and says, 'That will be five dollars.'
For that's what would happen in the absence of scales to measure the weights of things. People would make guesses about weight. There'd be a consensus view. And that consensus would change. One pound would become whatever most people thought one pound was. And almost certainly a pound would over time gradually weigh less and less. It would become devalued as a measure.
So also, in the absence of a set of moral principles against which to measure the value of actions, morality becomes devalued.
I was writing a few days ago about the decline of Christianity in the West. Christianity was what provided its set of moral principles, its moral weights and measures. Once those moral weights and measures were no longer available, or no longer used, morality became a matter of consensus. What was right and wrong became whatever everybody agreed was right and wrong. And this consensus was always gradually shifting towards the lowest common denominator.
And with smoking this consensus has been gradually shifting from tolerance of smoking towards intolerance. Smoking was once normal everywhere, and then became disapproved, and now it's all but illegal.
But even though there is a consensus, it's really only a consensus among senior doctors and epidemiologists and people like that. The consensus view on the ground (i.e. in the pub) remains pretty much what it has always been: nobody minds. The consensus among senior doctors is actually a false consensus. It's only reached by excluding ordinary people, and discounting their opinion. It's a consensus among 'doctors' and 'experts' and 'scientists'. Only their opinion counts.
And when it's come to be like that, then when you go into a greengrocer to buy a pound of potatoes, and are handed one small potato, and you complain, the grocer doesn't ask other customers their opinion, but calls up an Expert Potato Weigher. And this expert comes into the shop, and looks at the small potato through a magnifying glass, and sniffs it, and rolls it around in the palm of his hand, and says: 'It's exactly 1.173648 pounds.' And the grocer says, 'See. I told you! I was even being generous, so help me.'
It gets worse still. Once it's just a matter of consensus opinion what anything weighs, or what is right and wrong, then people who are determined or strong-willed are most likely to be able to push the consensus their way. It becomes a tug of war between two sides, with the 'consensus' being pulled first this way, and then the other way, entirely depending on how hard people can pull on the rope. Determined people win over less determined people. And determined, strong-willed people are zealots who are determined to get their own way.
And then when you go into a greengrocer to buy a pound of potatoes, and you question the weight of the small potato he offers you, the grocer gets angry and calls you a 'denialist' or a 'filthy sceptic'. You get shouted down. Unless you are yourself a zealot of the opposite sort, with a different burning certainty about the weight of potatoes. Everyone becomes a zealot of one sort or other. Everybody knows how to weigh potatoes. But nobody has a set of scales.