This philosophical time travel dilemma has come up frequently recently, even Jeb Bush was asked about it. For those unfamiliar with the Baby Hitler problem, it basically asks the question: if you could go back in time and kill Hitler as a baby, would you do it and would it be morally righteous?
The problem here is that it has become a proxy for stopping WW2 and the Holocaust and if that were the case then the choice is obvious. But we don’t know that is the case, maybe there is some kind of Zeitgeist that would ensure that roughly the same sequence of events occurs. And then maybe Hitler’s replacement is more effective and holds off on attacking Russia until he has subjugated the U.K. and the Third Reich becomes real and with it the concomitant decrease in the goodness of the world.
Unfortunately, this inability to determine the full consequences of our actions plays havoc with any attempt to ascribe morality to our actions. Maybe some Roman raider is faced with the choice of killing a young woman and ends up sparing her. This woman is the distant ancestor of Hitler. Are all of the people that Hitler murdered on that raider’s head as well? This despite choosing the more immediately moral choice. It presents a dour nihilism that would seem to prevent any action on the basis that you could be killing millions in the far future by drinking that coffee in the morning. You never know.
Maybe we should only consider the consequences of our actions out to the boundary of our ability to extrapolate the future? However, that means that the morality of an action is determined at some level by the person faced with the choice. If they are smarter or more informed then they can make better and more far reaching predictions. Then we have to ask how good we are at making predictions and assigning probabilities to various outcomes. This is impossible to verify, particularly at the decision point. Therefore, it comes down to the whims and personality of the person.
This leaves us with an untenable moral philosophy whereby good intentions are enough. I am sure Hitler believed the world would be better without any Jews, but I think we can all agree that genocide is evil. How can we possibly save any conception of morality? I don’t know and neither does philosophy.
This is where religion steps in saying that only a supreme omniscient being can extract us from this moral muddle. But then I have to ask how God does not fall prey to the same issues, why is his moral judgement invulnerable?