L1.2 Lottie’s second lesson on concepts
The next day, Lottie arrives late for her session with Hipparchus and offers no excuse. When he asks her what she thought of Millikan’s ideas, she looks at her rather large feet and says nothing. “I see” he says.
Reducing meaning via biological function
“Well we can cover that properly on some other day. But for now, the challenge Millikan faces stems from what wasn’t strictly true when I said that broadly Darwinian natural or biological functions have one foot in the realm of teleology or purpose and one in brute causation.
Imagine that some trait in an organism has contributed to its selective fitness in some way that we describe as a function. It might not have performed that function all the time (eyes have blind spots say) or even often (that may have to wait to a future session sex education)…”
“Yurgh! Gross!”
“But if the ecological payoff is great enough then we can explain the maintenance and proliferation of the trait because of the function. Er… ‘juices’ only sometimes make babies…”“I think I’m going to be sick.”
“… The function explains why it is useful - and if the benefit is great, the frequency can be low - and so what the trait is ‘for’. Another example: most mammal eyes have a blind spot because the optic nerve has to connect to the eye somewhere and where it does there are no light sensitive cells. You can find it by holding up two fingers, one in front of the nose one to the right, closing the left eye and while focusing on the left finger bringing both back towards your face. At some point, at some angle to your nose, the right finger will vanish. Now what's the function of the eye? What explains its success?”
“Well, to see, obvs!”
“But what it actually does is see the world at every point except the angle of the blindspot. Is that not therefore a more accurate specification of its function?”
“Err...”
“It may help to think whether having a blindspot explains the success of eyes or whether they are successful despite the blindspot. Surely, the function of the eye is to see everywhere. Engineering limitations makes its performance only a partial realisation of that. The moral seems to be this. Biological functions are more fine grained than just actual dispositions. They point to a world of purposes. Or so one naturally thinks.
Now imagine another inherited ‘trait’ that up until now has performed just the same function but will from tonight do something entirely different. Would it have been any the less successful in the past?”
“I suppose not.”
“So there’s no reason to think that by the standards of brute causation, even when moulded through natural selection, it would have been any the less successful. It has met the only standard biology sets. But it diverges from here on. Imagine a trait which meant that creatures were able to add 2 to other numbers. That might be helpful in storing nuts for winter. So far, this has only been expressed in the largest numbers that any numerate creature has added 2 to. But there are larger numbers we might need to know what adding 2 to would make. Has biology set a constraint on how to answer to these?”
“Hmm, perhaps not but this sounds fishy to me. Isn’t there some formula? Couldn’t the function just be the formula?”
“Indeed one might say that. And to persuade you it wouldn’t work I’d need to tell you about Ludwig Wittgenstein’s discussion of rule following. But roughly: if there is a formula it will need interpreting for each new number and we’ll have the same problem again.
So in other words, it seems that adding evolutionary selection to brute causation is not, fundamentally any better an idea than Fodor’s. When we look at nature through the lens of causes or biological past happenings we don’t reach meanings or concepts.”
“Hmm. But all that means is that two attempts to say something less silly about concepts than your first story haven’t worked. Your story still sounds silly to me, like a fairy story. How can there be abstract thingies in my thoughts?”
“That’s a slightly mangled question. But what about this? You don’t like the sound of abstract concepts because they do not sound real. They sound like fictions. And whatever their problems, the stories of Fodor and Millikan look grounded in reality: in causal mechanisms and computers or in biology. What if I tell you another story to make my first one seem more realistic? A story to kill a story. I’ll try to explain how meaning can be part of nature, but in another way.”
Davidson’s philosophy of language of the field linguist
Sadly at just this point, someone begins noisily strimming the grass that is trying to interfere with the Potting Shed’s vital vegetable plots and it becomes impossible for us to hear the rest of the lesson. (Sometimes life is just like French New Wave cinema.)
But later – Lottie only has lessons in the mornings and all afternoons are free – Lottie is sitting with pTravis the pterodactyl and Masongill the mole, two of the younger grownups who sometimes put up with her, in their den and, most unusually, is trying to remember and tell them about her lessson. Perhaps she thinks it will impress them!
“So this Yank David Donaldson was shipwrecked and washed up on a desert island but with natives. They wandered round the island shouting ‘Gavagai’ and other stupid things which gave him the creeps so he wanted to interpret what they were shouting. But he realised that he didn’t know what they were shouting Gavagai etc at. There were lots of creatures in the forest and birds and things and lots of wind noises. If he could have asked them what their problem was, he’d know the meaning of their words. But only when he knew the meaning of their words could he ask them!
So he decided to assume that they thought the same things as he did and had the same sorts of interests and were about as good at noticing things. He assumed they weren’t stupid (which sounds a bit stupid to me: I mean, natives!). He called that the…” looking at biro on the back of her hand: “Principle of Charity. So assuming they thought true thoughts and were, er… ‘rational’ then he could interpret them. He used his own ideas of what implied what and what was a reason to think what, a bit like a ruler to measure them.”
“But surely” interrupts Masongill “the natives would make mistakes and not be rational sometimes, just like us?”
“Yes but not normally. Not all the time. But wait a bit. Here’s the bit where it gets spooky. We’re just like that David Donaldson washed up on his beach. How did we learn language given that all we had to go on were stupid grown-ups shouting meaningless noises at us?! We had to do the same thing! So everyone who thinks and speaks and acts has to be largely rational!”
“Ah” says pTravis. “So that’s how this story helps with what your tutor said yesterday. You told us that abstract concepts sounded fishy, to you, or like stories. But this story suggests that it’s a bit like the numbers on a ruler that you use to measure things. Numbers are abstract too. But rulers don’t seem spooky or fishy. And so ascribing thoughts to natives, or each other, using this ideal rational or logical structure of thoughts is rather the same. And if different whole thoughts connect together by concepts they share that’s a bit like centimetres being dividable into millimetres. But we don’t think that there are lots of little millimetres running around like ants! You start with a whole ruler lined up against say my pipe here and you divide it up to see what fraction of the ruler the pipe corresponds to. And if the ruler were a metre rule you’d get the answer relative to that.”
At the mention of fractions, a shiver runs noticeably up Lottie’s short spine. But there’s one last thing she wants to say.
“I wrote this bit down: as well as the Principle of Charity there’s something called the Constitutive Ideal of Rationality. It’s the phrase for the fact that because we have to assume others are rational and because there’s no other way to get to thoughts or meanings except what happened on that beach – which didn’t stay on the beach! – then thoughts and meanings have to be, in themselves, rational. That means I’m rational!”
“Only mostly.”