We Need a Shared Understanding

What anchors our understanding, as researchers, of action, belief, knowledge and the rest?

The Argument

1. We as researchers need a shared understanding of belief and desire.

2. There are three potential sources of shared understanding: folk psychology, philosophy and decision theory.

3. Folk psychology does not provide a shared understanding.

4. Nor does philosophy.

   Therefore:

5. We need decision theory to provide a shared understanding.

To evaluate this argument we need to check premises 3 and 4.

Premise 3: Folk Psychology

Could our everyday expertise as mindreaders anchor our understanding? Consider Lewis (1972). He postulates that there are a set of platitudes concerning mental states which are common knowledge among us all. He also claims that if we assembled these platitudes, we could use them to define mental state terms like ‘intention’ and ‘knowledge’.

If this were true it would mean that we can rely on our everyday expertise as mindreaders to anchor our understanding, as researchers, of knowledge, intention and the rest. But is it true?

To illustrate how his view works, Lewis imagines that some important platitudes have this form:

‘When someone is in so-and-so combination of mental states and receives sensory stimuli of so-and-so kind, he tends with so-and-so probability to be caused thereby to go into so-and-so mental states and produce so-and-so motor responses.’ (Lewis, 1972, p. 256)

But what are these platitudes that are supposed to be common knowledge? Heider (1958, p. 12) offered what is probably still, more than half a century later, the most sustained, carefully developed attempt to ‘make explicit the system of concepts that underlies interpersonal behavior’.^[1] There isn’t much in Heider’s work that looks useful for defining ‘intention’ or ‘knowledge’.

It is also striking that not very much of Heider’s construction could plausibly be regarded as common knowledge among ordinary mindreaders. Heider relies on a mix of informal observation, imagination, guesswork as well as philosophers’ ideas (Ryle and Satre, for example), my guess is that we should regard the principles he identifies not as articulating an understanding that we all share but rather as an imaginative take on possible strategies for everyday mindreading. In fact, Heider’s approach is not that different from philosophers like Bratman or Alvarez.

But if Lewis were right about common knowledge of platitudes anchoring mental state terms, either Heider’s work should have turned out very differently or else there should be a lot less disagreement among the philosophers. This is why I think Lewis must be wrong.

(We might be able to use theories to specify models that help us characterise the expertise of ordinary mindreaders. But of course this presupposes a shared understanding of belief, desire and the rest in the first place.)

Premise 4: Philosophy

Could philosophical accounts provide a shared understanding of notions like belief and desire?

One obstacle is widespread apparent disagreement among philosophers.

Take intention, for example. It is not just that philosophers disagree on whether intentions are beliefs about the future (Velleman, 1989), or belief-desire pairs (Sinhababu, 2013), or something entirely distinct from both beliefs and desires (Bratman, 1987). Nor is it just that some think of intentions as essentially components of plans (Bratman, 1987 again) whereas others do not connect intentions with plans at all (Searle, 1983). Nor is it even that there is much disagreement about how intentions relation to action, to knowledge and to belief. Philosophers even disagree on whether intentions are mental states at all.^[2]

There is similar radical disagreement concerning knowledge, and concerning emotions.

The radical disagreement is an obstacle to using philosophical accounts to anchor understanding just because there is such deep and widespread disagreement among the philosophers.

But there is another, deeper reason for thinking that we cannot use philosophical accounts to anchor our understanding, as researchers, of knowledge, intention and the rest.

Philosophers have different, mostly unarticulated aims. Some philosophers seem to be proposing new ways of thinking in the hope that we adopt them. Others appear to be attempting to make explicit principles that are implicit in a particular tradition of law or in the activities of a particular historical culture. And of course some are trying to make systematic things that seem so obviously true that we can accept them without having any reason to do so (e.g. Lewis, 1969).

A further problem is that philosophical analysis often appear to rely on researchers’ own ideas about folk psychology (returning us to the problems of the previous section). Or so Nagel argues:

‘Unless there is a special reason to think that knowledge attributions work quite differently when we are reading philosophy papers—and [there is] evidence against that sort of exceptionalism—we should expect to find that epistemic case intuitions [which are among the things that inform philosophers’ views about what knowledge is] are generated by the natural capacity responsible for our everyday attributions of states of knowledge, belief and desire. This capacity has been given various labels, including 'folk psychology', 'mindreading', and 'theory of mind’’ (Nagel, 2012, p. 510).

If Nagel is right, appealing to philosophy to ground a shared understanding also inherits the problems of relying on folk psychology; so it is not even a genuine alternative.

Limit

To be clear, let me distinguish two claims:

1. We could (mis)use philosophical accounts of minds and actions to characterise various models of mind.

2. Philosophical accounts of minds and actions anchor a shared understanding of what knowledge, belief, joy and the rest are.

I am rejecting the second claim only. (The first claim has been very good to me, and I hope to keep misusing philosophical accounts of minds and actions.)

Conclusion

The argument works: we lack a shared understanding of belief and desire. This is where decision theory may be useful: it promises to a formal framework which can elucidate notions of belief and desire, thereby providing a shared understanding (Jeffrey, 1983).

Optional Extra: Operationalization

A third potential source of shared understanding (in addition to folk psychology and philosophy) is operationalisation. A variety of scientists have offered operationalisations of abilities to attribute mental states. Perhaps we could use these to anchor a shared understanding?

This is a tempting idea, but it faces two problems. First, we do not really know much about the structure of Theory of Mind, and different researchers use different taxonomies (Happé, Cook, & Bird, 2017; Beaudoin, Leblanc, Gagner, & Beauchamp, 2020).^[3] Second, while there is some evidence that a wide range of false belief tasks appear to test for a single underlying competence (Flynn, 2006, p. 650; Wellman, Cross, & Watson, 2001), when we turn to theory of mind tasks more broadly we find that different theory of mind tasks appear to test for different things in the sense that an exploratory factor analysis fails to find that they load on a single factor (Warnell & Redcay, 2019).^[4]

This means that when faced with the question of what anchors our understanding, as researchers, of action, belief, knowledge and the rest it is not enough simply to point to an operationalisation.

This does not mean, of course, that operationalisations are irrelevant, only that they cannot currently provide a shared understanding of notions like belief and desire.