We do not have to make self- sacrifice a necessary element of altruism. We can regard people as altruists because of the kind of interests they have rather than because they are sacrificing their interests.

Living a minimally acceptable ethical life involves using a substantial part of our spare resources to make the world a better place. Living a fully ethical life involves doing the most good we can.

It is easy for us to criticize the prejudices of our grandfathers, from which our fathers freed themselves. It is more difficult to search for prejudices among the beliefs and values that we hold.

when we make ethical judgments, we must go beyond a personal or sectional point of view and take into account the interests of all those affected, unless we have sound ethical grounds for doing otherwise. (...) The essence of the principle of equal consideration of interests is that we give equal weight in our moral deliberations to the like interests of all those affected by our actions. (...) an interest is an interest, whoever's interest it may be.

My students often ask me if I think their parents did wrong to pay the $44,000 per year that it costs to send them to Princeton. I respond that paying that much for a place at an elite university is not justified unless it is seen as an investment in the future that will benefit not only one’s child, but others as well. An outstanding education provides students with the skills, qualifications, and understanding to do more for the world than would otherwise be the case. It is good for the world as a whole if there are more people with these qualities. Even if going to Princeton does no more than open doors to jobs with higher salaries, that, too, is a benefit that can be spread to others, as long as after graduating you remain firm in the resolve to contribute a percentage of that salary to organizations working for the poor, and spread this idea among your highly paid colleagues. The danger, of course, is that your colleagues will instead persuade you that you can’t possibly drive anything less expensive than a BMW and that you absolutely must live in an impressively large apartment in one of the most expensive parts of town.

When my ability to reason shows me that the suffering of another being is very similar to my own suffering and matters just as much to that other being as my own suffering matters to me, then my reason is showing me something that is undeniably true. ... The perspective on ourselves that we get when we take the point of view of the universe also yields as much objectivity as we need if we are to find a cause that is worthwhile in a way that is independent of our own desires. The most obvious such cause is the reduction of pain and suffering, wherever it is to be found.

We are responsible not only for what we do but also for what we could have prevented.

Science does not stand still, and neither does philosophy, although the latter has a tendency to walk in circles.

Human social institutions can effect the course of human evolution. Just as climate-change, food supply, predators, and other natural forces of selection have molded our nature, so too can our culture.

Ethics seems a morass which we have to cross, but get hopelessly bogged in when we make the attempt.