Other minds

How anyone knows that other beings have experience, given that only one case is ever available from the inside.

Theme: Mind, self and consciousness
Tradition: Analytic
Term fixed: 1865

In plain terms

You have direct access to exactly one mind. Everything you know about anyone else's comes from behaviour - what they do, what they say, how they react.

The traditional worry is that this is a weak inference. It generalises from a single instance, which no other science would accept, and the conclusion cannot be checked against the thing it is about.

In practice nobody has ever doubted it, and that is itself philosophically interesting - it suggests the belief is not really the conclusion of an argument. But the question stops being idle the moment the usual behavioural evidence is missing: a patient who cannot move or speak, an animal whose reactions we cannot read, a machine whose reactions we can read too easily.

As a philosopher would put it

The argument from analogy holds that we observe a correlation between our own mental states and our behaviour, observe similar behaviour in others, and infer similar states. The standard objection is that it is an induction from one case, which is unusually weak.

Wittgenstein reframes the problem. If a term like pain got its meaning from a private inner sample, no one could check their own use of it, and there would be no distinction between being right and seeming right; so the public criteria are not evidence for something hidden but part of what the word means. On this view the sceptical problem is not solved but dissolved, and the demand for something behind the behaviour rests on a mistaken picture of how the words work.

Alternatives include treating other minds as the best explanation of behaviour rather than an analogy, and the phenomenological line that other people are given as embodied subjects in perception rather than inferred - Merleau-Ponty and Scheler both argue that we see anger in a face rather than deducing it.

Where you meet it

In 2006 Adrian Owen's group published a study in Science of a twenty-three-year-old woman who met every clinical criterion for the vegetative state after a road accident: no behavioural sign of awareness, sustained over months.

In the scanner she was asked to imagine playing tennis, and then to imagine walking through her house. The two tasks produce different and well-characterised activation patterns, and hers were indistinguishable from those of healthy volunteers given the same instructions. She repeated it on command.

Subsequent work with larger groups found a similar response in a minority of patients diagnosed as vegetative, and some were later able to answer yes-or-no questions by choosing which image to imagine. The problem of other minds turned into a clinical protocol - and it did not stop being philosophical when it did, because the patients who show no response have not thereby been shown to have no experience.

What is actually disputed

Whether the problem is a real epistemic gap or a confusion about language.

Wittgenstein's dissolution is influential and not universally accepted: critics argue that showing pain-talk depends on public criteria does not establish that there is nothing further to be right or wrong about, and that the sceptical question survives the linguistic point.

The practical version has no accepted answer at all. The criteria for attributing experience to animals, to patients with disorders of consciousness, and to artificial systems are contested in every direction, and they pull apart: a system that produces highly convincing verbal behaviour may have nothing behind it, while a patient producing none may have everything. Any criterion drawn to include the second tends to include the first, which is the shape of the difficulty.

Commonly confused with

theory of mind in psychology That is a developmental capacity to attribute mental states, which children acquire. The philosophical problem is whether the attributions are justified.

Defined against

Subjectivity The problem exists precisely because experience is available from one position only, which is what subjectivity names

Philosophers

John Stuart Mill The argument from analogy in its standard form
Ludwig Wittgenstein The private-language argument, and the reframing of the question
Maurice Jean Jacques Merleau-Ponty Other people perceived as embodied subjects rather than inferred
Edmund Husserl The constitution of the other in experience
René Descartes The starting point that makes the problem inevitable

Works

Philosophical Investigations The private-language argument
Phenomenology of Perception The perceptual account of other subjects
Meditations on First Philosophy Where certainty is restricted to one's own case
The Concept of Mind The behaviourist dissolution
Totality and Infinity The other as an ethical rather than epistemic problem

Schools

Ordinary Language Philosophy Where the problem is reframed as one about meaning
Phenomenology Where other subjects are perceived rather than inferred
Cartesianism The starting point that makes the problem inevitable
British Empiricism Where the argument from analogy is developed

Related concepts

Consciousness 1641 · Qualia 1929 · Intersubjectivity 1913 · Mind c. 450 BC · Compassion c. 450 BC

Mill gave the argument from analogy its standard nineteenth-century form; Wittgenstein's private-language argument reframed the whole question as one about meaning rather than evidence.