In an earlier post, I argued against materialism on the grounds that persons are non-fungible but material objects are fungible or at least persons are non-derivatively non-fungible, while material objects are at best derivatively non-fungible.
Here's a pathway to arguing that if naturalism is true, then at least some persons are fungible. Since no persons are fungible, it follows that naturalism is false.
Start with the thought that:
- Something wholly composed of fungible parts is fungible.
But (1) may not be quite right. After all, arguably, the Mona Lisa is (derivatively) non-fungible, but all the elementary particles making it up are. There would be no loss if we replaced the particles of the Mona Lisa one by one. The non-fungibility of the Mona Lisa is grounded in the non-fungibility of the arrangement of the parts: If suddenly the Mona Lisa was burnt up, but by coincidence the particles in the ashes and smoke arranged themselves in an exactly similar arrangement, something of value would be lost. There is something special here about the arrangement.
What makes the arrangement of the Mona Lisa's particles special is the specialness of the artistic process that produced that arrangement. This suggests:
- Something wholly composed of fungible parts arranged by a fungible process is fungible.
Now you or I perhaps did have our parts get arranged by a non-fungible process: our parents' loving union. But even persons produced by in-vitro fertilization had their parts arranged by our biological parents' bodies through their gametes, and the process of gamete production in a person is arguably non-fungible.
However, at least one person—namely, a first human person—has no person as a biological parent, on pain of an infinite regress. If theism is true, that person may still be the product of a non-fungible process of creation by a (divine) person. But naturalism rules out not only dualism but also theism. A naturalist who does not believe in an infinite past will have to hold that there is a first person who is in no way produced by a person. And there it seems that the process producing that first person is fungible—it plausibly doesn't matter value-wise which of two exactly similar brute animals mated with a brute animal to produce a person. (If it is responded that primates like those we descend from are themselves non-fungible, then just take the argument further back in our evolutionary past.)