I think that in ancient Democracy, in Athens, there was indeed some harshness, such as the rather wide employ of the death penalty, which lead to the conviction of Socrates, I remember also the case of the generals who won the sea-battle of Arginuses, but were put to death by the people, without a trial, for having left to die at sea the sailors of the ships sunk by the enemy (Spartans), by omiting to rescue them.
To this facts we must oppose that there was a Tribunal competent for the killing of slaves, that, in the Athenian army was not present the decimation (putting to death one every ten soldiers), if a ploton didn't fought well, as in the Roman army, but was provided a lawfull judgement.
So it was not really cruel.
We must add that today, if in Europe we don't have the death penalty, we have poisonous factories (chemical, asbetos etc.) which cause cancer for the workers. So, if on one side we have abolished the death penalty , on the other we have introduced death for honest workmen.
As far as values are regarded, I think that to say one think is right, another is wrong, absolutely, is very difficult, if not impossible, the reality being very, very complex, so one cannot codify it.
We should leave this debate to the political discussion.
Aristotle and, I think also Plato, condemns lending money for an interest; this is one of the motors of modern economy, indeed I think they were right, and that we should renounce to progress and return to ancient times.