I agree with Varner and Scruton that the more one thinks of one's life as a story that has chapters still to be written, and the more one hopes for achievements yet to come, the more one has to lose by being killed. For this reason, when there is an irreconcilable conflict between the basic survival needs of animals and of normal humans, it is not speciesist to give priority to the lives of those with a biographical sense of their life and a stronger orientation towards the future.
Peter Singer, Practical Ethics
animals, ethics, preference, utilitarianism