Nagel once claimed that it is psychologically impossible to believe the Reductionist View. Buddha claimed that, though it is very hard, it is possibl… - Derek Parfit

Take a Swede who is proud of his country’s peaceful record. He might have a similar divided attitude. He may not be disturbed by the thought that Sweden once fought aggressive wars; but if she had recently fought such wars he would be greatly disturbed. Someone might say, “This man’s attitude is indefensible. The wars of Gustavus, or of Karl XII, are as much part of Swedish history.” This truth cannot, I think, support this criticism. Modern Sweden is indeed continuous with the aggressive Sweden of the Vasa kings. But the connections are weak enough to justify this man’s attitude.

We live during the hinge of history. Given the scientific and technological discoveries of the last two centuries, the world has never changed as fast. We shall soon have even greater powers to transform, not only our surroundings, but ourselves and our successors. If we act wisely in the next few centuries, humanity will survive its most dangerous and decisive period. Our descendants could, if necessary, go elsewhere, spreading through this galaxy.

Classical Utilitarians...would claim, as Sidgwick did, that the destruction of mankind would be by far the greatest of all conceivable crimes. The badness of this crime would lie in the vast reduction of the possible sum of happiness.