Generalization would lead to the recognition of value in possible future experiences, in the means to them, and in the lives of creatures other than ourselves. These values are not extra properties of goodness and badness, but just truths such as the following: If something I do will cause another creature to suffer, that counts against doing it. I can come to see that this is true by generalizing from the evident disvalue of my own suffering[.]

Thomas Nagel, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False, Oxford, 2012, p. 77