Unfortunately for ethical egoism, the claim that we will all be better off if every one of us does what is in his or her own interest is incorrect. This is shown by what are known as "prisoner's dilemma" situations, which are playing an increasingly important role in discussions of ethical theory... At least on the collective level, therefore, egoism is self-defeating - a conclusion well brought out by Parfit in his aforementioned Reasons and Persons.

...the proposed air force and army experiments were designed so that many animals would suffer and die without any certainty that this suffering and death would save a single human life or benefit humans in any way at all; but the same can be said of millions of their experiments performed each year in the United States alone.

Somebody who eats twice as much factory-farmed products as he or she needs to is clearly doing twice as much damage to the planet. From a utilitarian point of view, that's twice as bad.

There are many cases in which gifted children have done great things without special school programs. There are also gifted kids who have been to special schools and achieved nothing that has benefited the world as a whole. Without solid evidence, I have no confidence that funding school programs for the intellectually gifted would do more good than the most cost-effective programs to help people in extreme poverty.

Sci-fi is often a metaphor. I think it's more the themes and questions that science fiction raises rather than the exact predictions that should guide us.

Whereas the property-owning middle class could win freedom for themselves on the basis of rights to property--thus excluding others from the freedom they gain--the property-less working class possess nothing but their title as human beings. Thus they can liberate themselves only by liberating all humanity.

Grain that is used to feed animals that end up on our tables as turkeys and hams could have gone to feed starving people.