Alexander Pruss's Blog

Consider this familiar argument: We cannot know about the sorts of things that don’t causally affect us. Abstract objects are the sort of...

It just hit me how puzzling Platonism is. There are infinitely many abstract objects. These objects are really real, and their existence see...

Suppose that we think of properties as the things that fulfill some functional roles: they are had in common by things that are alike, they ...

If we have an Aristotelian picture of abstracta, we should expect that what mathematical objects exist differs between possible worlds. For...

It seems that music is a sound, and sound is constituted by vibrations of a surrounding medium, i.e., typically air. But you can listen to a...

Consider this "easy ontology" argument: There are no unicorns. So, there are zero unicorns. So, there is a zero. This se...

Start with the Aristotelian thought that abstract entities are grounded in concrete ones. Add this principle: If x is grounded ...

Here is an argument against presentism: If presentism is true, then to exist is to presently exist. Abstracta exist but do not ...

I find sets to be very mysterious candidates for abstract entities. I think it's their extensionality that seems strange to m...

Benacerraf-style arguments that numbers couldn't be any particular collection of abstract entities (say, some particular set-theore...

Suppose that none of the participants in World War II had ever existed. Then it would have been impossible for World War II to oc...

I was reading the SEP entry on nominalism by Rodriguez-Pereyra. Rodriguez-Pereyra sees nominalism as basically the rejection of causally i...