This question was presented @ reddit and comes up from time to time. It might be a good exercise to discuss various ways to tackle this.
Q. Must humanists believe in the existence of objective moral values?
According to some definitions of humanism I have seen, humanists must believe in objective morality, i.e moral realism. Is this correct, to your mind? Or can a person be a humanist and not believe that objective moral values exist?
R. I can't speak for most humanists, I suspect there are various opinions out there, but:
- I'm an Epicurean moral realist, and YET
- I think people who search for an "objective" morality are chasing a ghost.
I don't think objectivity needs to be a feature of moral realism. The third Scholarch of the Epicurean School, Polystratus, argued that pleasure and aversion are emergent / relational properties of bodies, and that they are "objective" insofar as they are real and experienced as real, but they are not "objective" in the sense that they are subjective, personal experiences. I believe "objective" is an arbitrary, empty idealism, and that there's no reason whatsoever to suppose that the things that make life worth living have to obey the logic of having to be "objective".
Notice that Polystratus' pleasure-based morality is firmly rooted in the physics, and in the study of nature. Notice the language: "emergent properties of bodies", and he compares this to how a magnet attracts some metals but not others, or how some herbs cure some people but not others, or how peanuts give allergic reactions to some people but not others. These relational properties of matter are REAL, and obey natural processes. And he's saying that the complexities of pleasures and aversions in all our choices and avoidances, and in all our interactions both social and physical, obey similar principles.
There are no absolutes in nature, all things are relational. Absolutes are Platonic, imagined. Time is relative. Space is relative. Motion is relative, and so is gravity or the attraction and movements between the bodies. Why should it be any different in the realm of natural ethics?
So I would say NO, humanists "must" not (or are not obligated) to chase the ghost of "objective" morality (this is the great error we find in people like Sam Harris who have not studied Epicurean ethics), and yet this does not take away from having a fully scientific, useful, pragmatic morality.