Thursday, November 3, 2011

Causal Relevance and Apples

I was thinking about something Tillman said last class - that the VI/Merricks view meant that apple trees but not apples exist - and this seems like a serious problem for the view. Apple trees exist because the collective activity of an apple tree's parts somehow constitute a life, and it seems that the collective activity of an apple seed's parts should also constitute a life - after all, the seed grows into the tree, and if the seed is not alive, then neither is the tree. So seeds exist.

The problem here is apples.

Apples aren't alive (at least, not by any biological definition) and they are just as causally irrelevant as baseballs - the scent, taste, shape, crunchiness, hardness, etc., of an apple can be explained solely in terms of the collective activity of its atoms... So apples certainly don't exist.

But apple seeds do, and apple seeds are part of an apple - in fact, seeds are the very reason that apples are produced! It certainly wouldn't be reasonable to think that an apple doesn't exist but a part of an apple (the seeds) does exist, as if it were possible for some apple parts to exist by merit of their life and other apple parts to only be atoms arranged apple-wise. That's strange. There would have to be a really good reason to actually believe that.

To sum up: If causal relevance is the only factor VI/Merricks has to offer in determining whether something exists, then trees and seeds exist but fruit (which contains seeds) doesn't exist, because the fruit is causally irrelevant. And that makes no sense.

I think causal relevance just isn't enough to decide whether something exists. What does everyone else think?


  1. I think your right that PVI/Merricks must claim that there is no apple but there are the apple seeds. I also think your right that this is an odd conclusion.

    Maybe I am just being picky, but I just want to point out that they wouldn't claim that the seeds are apple parts that exist (or that the apple doesn't exist but some apple parts do, namely the seeds). The would just claim that there are apple seeds. (sorry if that's what you meant, I often word things wrong as well)

    I think their view is not that odd though. So as a general point, when we ask "when do some things compose a thing" we can think of the question being, what is the metaphysical glue that holds things together. PVI/Merricks think this metaphysical glue has got something to do with causality. If we have a collection of things and we throw them through a window, it seems odd to also add that there is also this thing, over and above the collection of things, that also went through the window (the composite). Why posit that. But when we consider a life we notice that the life has something going on over and above what just its parts have going on. This extra thing seems relevant enough to count as the metaphysical glue, because it is something substantial. Life is something that makes a causal difference in the world that apples and baseballs just don't.

    So with regards to the seeds, well yes there a composite object because they are held together with this glue, namely life, that the collection of bits arranged apple wise don't have.

    All that said, I would also agree that causality might not be the only thing in our metaphysical glue. I also think another good question might, "is life actually a causal power over and above the parts of the thing containing the life". What if life is just like the way a car engine works. You put all the bits in the right place, make some chemical reactions and all the bits move around in a nice way. Maybe life is like that, so then there is no extra causal power going on.

    Maybe somethings never compose a thing?.....

    Last point. If causality is not the only thing relevant to composition, what is?

  2. Quick biology lesson: Apple trees are flowering plants. When pollen from one flower fuses with an ovule inside the ovum of another flower, the ovule develops into a seed and the ovum develops into fruit. The purpose of fruit is mainly seed dispersal - an animal will eat the apple, the seeds pass through its digestive system unharmed and are then deposited far enough from mother tree that baby tree will not crowd out mother when it grows up.

    Basically, while the apple is developing on the tree, it's taking part in the life process of the tree, although it's still causally irrelevant by itself. It just seems strange to say that seeds exist but their neighbour (the fruit encompassing the seeds) are just atoms arranged fruit-wise...In some ways the view is similar to saying that people exist but their bodies don't.

    If life is the magic ingredient for making some things compose a thing, the question of when some things compose a thing becomes the question of when some things compose a life. We could use the biological definition of life, but viruses are an exception to the rule so it doesn't seem good enough. Maybe life is special because the collective chemical reactions make something more happen - sort of like the way the engine running makes the car move. Maybe that's the extra causal power.

    I don't know what else other than causality would make up the metaphysical glue, but I do know that the universe is generally complex - usually there is more than one factor determining something. Relying on just causality for composition seems to run counter to the way the universe works.