This is a horrible thought. It makes sense if you do the math. There is more to life than logic and reason alone. The human being is not merely a biological organism like a rainbow trout priced at ten dollars a pound.
Obviously. That's why it's an unanswerable dilemma for most of us. On the one hand the math says it makes sense. On the other, killing a baby is equally horrific to us.
But I would point out that I never actually said “kill a baby”. If you could go back in time, why would you kill baby Hitler? You could likely drastically change history if you just killed baby Hitler’s dickhead father before he had a chance to screw baby Hitler up beyond redemption. But I never actually even said anything about going back in time.
Instead, look at the ending of Star Trek 2: The Wrath of Kahn. One person (Spock) sacrifices himself to save hundreds. In that particular case he would have died either way, so it wasn’t as noble as they made it out to be, but still pretty noble.
But even that has pretty much zero meaning until you assign it specifics. Morality is a fickle thing. When I ask you about killing one person to save millions your brain automatically goes to a specific instance. But there are endless possibilities there.
What if you were given a choice: Kill one random person you do not know or a bomb will go off in New York, killing millions? That’s still a pretty tough choice.
Now, what if that random person you do not know isn’t random, it’s the person controlling the bomb? Kill the person who is going to murder millions to save their lives. Now the moral dilemma lessens because you’re killing a would-be murderer who would be directly responsible for the loss of life you are preventing.
What if there are a million people tied up and one man going down the line and stabbing them, one by one? Men, women, children, all in a line. You have a gun, but you can’t get to him to physically restrain him. You have a shot, but only a kill shot. You kill him or you watch him kill. Now, for most of us, there is no dilemma at all. You shoot. But for extreme pacifists letting the million people die would be better because it would mean that they, personally, were not a party to violence. They may argue that they do not have responsibility for what another does, only their own actions, and inaction is the only thing that keeps them from bearing responsibility for the loss of life.
So you see, all of these hypothetical are very situational and all beside the point I was making. That point was that whether the individual or the group was more important was also very situational. In a political party the party is more important than any member and the country is (or at least should be) more important than the party. In that case a group is more important than an individual, but less important than a second group. There are situations in which each way is true, and even that is always subjective.