if someone from the future shows up to kill a baby you probably bitchslap him.
I certainly would and would find the idea abhorrent even with the benefit of foresight, as I suspect would most people.
On reflection, I realise I probably misinterpreted Ellderon's comment so if I have mistakenly assumed "edgelords be here" then I apologise.
Surprisingly millions of babies are killed every year and as abhorrent as it is it's considered to be "lawful"
Which takes us back to our lawful character alignment topic.
I don't know where "lawful stupid" began and you, Vometia, are absolutely correct. It is stupid how you can pick up an item that belongs to someone else and automatically be considered a thief like in oblivion when trying to fix an area you may have accidentally blown up. In that case one would consider the fireball launched at a wall of alembics a crime rather than picking up an alembic and putting it back on the shelf. However, I digress. Being Lawful is simply that you believe in laws. Laws help to keep things in a state of order be it the laws of physics or the laws of man. For evil or for good it doesn't discriminate. If your Paladin is lawful good then they have a strong sense of both preserving order and protecting/helping people and society.
So if your Paladin were enacting executions all over the place for things like shoplifting this "would" be acceptable if that were the "law" in that location and crimes were all punishable by death. A Paladin who's greater good is preserving society would call this good. Now in a D&D world there's a chance you can convince such a Paladin that the system he's serving is evil though that DC would be strongly dependent on how well the laws are keeping the peace and happiness of the society.