Does reduction of the self hinder moral behavior?

Parfit is a Realist about morality. He thinks that moral truths are fundamental truths and have the same ontological status as logical/mathematical and "metaphysical" truths.

Actually, I should make a distinction, here. Parfit has a specific view of ontology that is somewhat unique among analytic philosophers. He's very much a Kantian about metaphysics.

He argues that there are two senses of "exist": narrow existence and wide existence.

Roughly, something exists in the narrow sense when it is the sort of thing we can "get a firm (mental) grip on", so to speak. Ordinary, concrete (i.e. actual) objects all exist in the exist narrow sense. There is nothing mysterious about them and we can give a complete description of them. The class of narrow existents is the domain of reality.

A thing exists in the wide sense when, necessarily, it partially obscure. There are two sorts of wide existents. One is the class of possibilia. Possibilia are non-actualized ordinary objects, like your possible future children. They aren't real, but they could be. If they were to become real, we wouldn't find this to be mysterious.

There is a second class in the domain of wide existents. He thinks that we have certain intuitions about logical, metaphysical and normative things that we must believe ("truths" about them,) but that we have no access to the truthmakers for such intuitions. This restricted access is necessary insofar as the constraints are in virtue of our cognitive capacities: we just don't have the apparatus to comprehend the truthmakers in their entirety. In other words, we just know some things are true, even though we can't explain what makes them true. Their truth makers are necessarily mysterious.

In Parfit's account, "good"/"evil" etc. aren't strictly "real" in that necessarily, they are partially obscured from our awareness. However, they are the at the fundamental basis of reality. So, unlike possibilia, we have certain, albeit obscure, awareness of them in virtue of their effects.

/r/askphilosophy Thread