Thread by @tscottphillips

Naturalism vs formalism: A thread.

(Or: How I learned to stop worrying & love informality)

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#science #philosophy #whyiliketheideasthatilike

TL,DR: naturalism is a basic commitment of scientific explanation, & formalism a tool that can help achieve it – yet people too often prioritise the latter over the former.

Elaborating on comments I've made here before, in conv w @IrisVanRooij, @JCSkewesDK, @wgervais, et al.

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One preliminary comment.

Usually I try to avoid "I know what I'm talking about" comments – you should just let your arguments & ideas do the talking! – but in this case it seems worth mentioning.

I have a degree in Pure Mathematics. This is not math-phobia.

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So, to define terms.

Formalism: roughly, any expression of an idea in exact, precise terms. Usually means either math or computer models.

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This exactness makes everything explicit, in particular definitions and assumptions. It also facilitates quantification, and hence allows for direct comparisons.

So formalism is obviously a Good Thing. It's a super important tool for science.

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Naturalism is a more slippery notion, but roughly: an explanation / idea / theory / etc is 'naturalised' if its assumptions / links to neighbouring disciplines / unaddressed issues / etc are at least coherent to experts in the relevant fields.

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I often think of it as 'handing over sensible questions'. All science hands over questions to its neighbouring disciplines. Are those questions coherent / accepted as coherent by the people you're handing them to?

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Another way to put it is problems vs mysteries.

All scientific ideas leave some matters unaddressed. Are those unaddressed matters problems (for other disciplines to address?) or mysteries?

Here's a relevant passage from @dansperber's 'Explaining Culture'.

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One high-profile example is the model of the rational actor in economics. The core complaint of behavioural economics is that the rational actor is not a model that neighbouring disciplines (specifically psychology) recognise as coherent.

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In other words: although classical economics is highly scientific in its methods – and indeed it is awash with formalisation – it is not naturalised. Another line from Sperber (Explaining Culture, p.4).

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It seems to me that the rational actor has a lot of company There are many notions in the human sciences for which their naturalism is at the very least unexamined.

Bias, learning, culture,... the examples are many. Often (not always) these words hide mysteries.

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But don't get me wrong. I'm not about to say that all unnaturalised science is worthless. Far from it! Plenty of good science can be done by sidestepping these issues.

I do however complain that naturalism is too often treated as secondary to formalism. This is a mistake.

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Crucially, formalism and naturalism *are orthogonal*. All combinations are possible.

formal / informal
x
naturalised / unnaturalised

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Some theories are formal, but not much naturalised. Classic example: the rational actor (see above).

Others are highly naturalised but informal. Classic example: Darwin's presentation of the theory of natural selection.

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What happens when these two desiderata, formalism and naturalism, aren't fully aligned?

Seems to me that scientists – and indeed the institution of science itself – too quickly & too often privilege formalism over naturalism. Math is sexy.

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The word 'rigour' often appears at this point. It's sometimes used as a misleading synonym for formal. "..a rigorous theory of X...".

The hidden implication is that unformalised work is unrigorous. And no doubt that is true sometimes. But definitely not always.

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Some work in the social & cognitive sciences has naturalism as its raison d'être. The goal is to hand over sensible questions/assumptions to *all* the relevant disciplines. Developing ideas that meet this goal is serious, hard scientific work, and it demands rigour.

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Incidentally, some scientists seem to think that such work is, in some real sense, *not science*. They call it philosophy instead, as a way to sidestep the issues that get raised by naturalistic thinking.

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Anyhow, two pet examples from my own areas: Relevance Theory; Cultural Attraction Theory.

Both are highly naturalistic, and indeed that's exactly why I've been drawn to them and work on them. Deep engagement with the relevant findings and thinking from neighbouring areas.

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I won't go into details here – that would be for another time & other threads – but I think a lot of competing theories in these areas** embrace formalism at some expense to naturalism.

** i.e. cognitive pragmatics for RT; cultural evolution for CAT

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The Q is: If & when it's necessary, are you willing to sacrifice the obvious benefits of formalism, to maintain genuine coherence across disciplines?

I am, and I think that for those of us who want to do basic science about what makes us human, this is the right choice.

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(It's not always the right choice, especially if you're doing applied science. But for what I do it is right, I'm sure.)

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This is why I'm always taken aback when I see people say that the best work in an area is the stuff that has a mathematical foundation; or when they say that we need is more formalism, without making any mention of naturalism.

That's all prioritising a method over a goal.

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So in sum: of course formalism is desirable and important – but sometimes a naturalised idea isn't (yet) formalised. When that happens, what do you prioritise?

I'll always go with naturalised & informal over formal & unnaturalised. What about you?

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