Keith’s Conundrums: What Is a Boundary?

Keith Douglas

The Conundrums from last month asked about function of organs in light of the fact that we know that they were not designed but arose by various evolutionary processes (thanks, Darwin and others!). This puzzle was done in honour of Darwin Day and I hope you caught that part of it!

Personally, I find it reasonable to assume that something can acquire function despite being composed out of non-functional parts — otherwise, everything is functional. Daniel Dennett and others have raised this point; however, it could still be (like Mario Bunge and Martin Mahner hold) that functions are only available to sufficiently advanced animals and thus organs do not exhibit functions; behaviours of these animals do. Oddly, like with Bunge on computational theories of mind and AI, he sounds very Wittgenstinian here, which would probably have outraged him. No matter; the great teacher (of me at least) I think is wrong here — in all three cases.

However, although Bunge and Mahner are wrong in my view, I am not willing to play the adaptationist card, like Dennett does. Dennett thinks one can appeal to natural selection to characterize, ontologically speaking, what function organs have — even though epistemically we may never know for sure. The idea is that a) there was, at some point, some selective pressure in one direction rather than another, b) that pressure determines what role an organ has in an organism’s life cycle, etc., and c) the role is therefore the function. It may not be describable in ordinary language, or even be discoverable (as mentioned) but it is so to say, a stable part of the “state space of behaviours” (to use Bunge language) of that species of organism. This also allows for “misuse” — and cases where it is just not either misuse or function. (See Dennett’s monumental Darwin’s Dangerous Idea.)

Why am I skeptical? I think Dennett’s view is correct in some cases, perhaps, but it does have the consequence that some organs have no function at all or have lost their function. This sounds at first glance to be fine — one thinks of the human appendix — but perhaps not. Take colour vision; Pinker and others argue vehemently that this is an adaptation.

Suppose, however, that Pinker and the evolutionary psychologists (and Dennett himself!) are right that some of colour vision is an adaptation, but not all. In particular, suppose some of the reasons we see that way arose as an exaptation. Then we’d have to say that perhaps so-called red-green colourblindness was not pathological, and correcting for it (e.g., by early diagnosis and awareness campaigns) was not medically warranted. Are we willing to do this?

As we have seen in this discussion, I am of several minds. I hope you too feel some perplexity here. I still do!

On to the next Conundrum. We continue in the field of metaphysics meets biology and the biotechnologies.

What Is a Boundary?

Here are some questions to think about:

• Were you ever a part of your mother? (I assume my audience is human when I ask this question!)
• Were you ever a fetus?
• Were you ever a gamete?
• Were you ever a carbon atom?
• What is a boundary, metaphysically speaking (or otherwise)? How does it relate to other metaphysical categories like part, whole, property, thing? Does this bear on the previous questions in any interesting way?

I owe the idea behind these questions to the 2018 proceedings of the meeting of the Philosophy of Science Association. Apparently the scholarly meeting had a session on the metaphysics of pregnancy — some interesting stuff there, even for us who are child-free by choice.