How can I know that other minds exist?

Other minds: The problem of justifying belief that beings other than oneself have conscious experiences.

Analogy: Reasoning from the link between one's own behaviour and experience to similar cases.

Behaviourism: An approach that explains mental concepts through behaviour, dispositions or public criteria.

Qualia: The felt, first-person qualities of experiences such as pain or colour.

Solipsism: The position that only one's own mind is known, or perhaps exists.

John Stuart Mill: Mill develops an argument from analogy: other bodies act as his body does when he experiences thoughts and feelings, so similar behaviour supports belief in similar inner causes. The argument makes other minds probable, but begins from a single directly known case — one's own. Ludwig Wittgenstein: Wittgenstein challenges the picture of mental language as labels attached to wholly private objects. Words for pain and emotion gain their use within shared human practices. Another person's pain is not inferred in every encounter as though it were an invisible object hidden behind their behaviour. Gilbert Ryle: Ryle rejects the mind as a private ghost operating a public machine. To describe intelligence, belief or character is often to describe dispositions expressed across behaviour and circumstances. His approach narrows the apparent gulf between inner mind and outward life, but faces the possibility of convincing imitation.

Ludwig Wittgenstein: Wittgenstein challenges the picture of mental language as labels attached to wholly private objects. Words for pain and emotion gain their use within shared human practices. Another person's pain is not inferred in every encounter as though it were an invisible object hidden behind their behaviour. Gilbert Ryle: Ryle rejects the mind as a private ghost operating a public machine. To describe intelligence, belief or character is often to describe dispositions expressed across behaviour and circumstances. His approach narrows the apparent gulf between inner mind and outward life, but faces the possibility of convincing imitation. Thomas Nagel: Nagel emphasises the subjective character of consciousness: there is something it is like for a conscious creature to exist. Objective knowledge of behaviour and physiology may grow without capturing that point of view, preserving a gap between evidence about a being and access to its experience.

Gilbert Ryle: Ryle rejects the mind as a private ghost operating a public machine. To describe intelligence, belief or character is often to describe dispositions expressed across behaviour and circumstances. His approach narrows the apparent gulf between inner mind and outward life, but faces the possibility of convincing imitation. Thomas Nagel: Nagel emphasises the subjective character of consciousness: there is something it is like for a conscious creature to exist. Objective knowledge of behaviour and physiology may grow without capturing that point of view, preserving a gap between evidence about a being and access to its experience. John Stuart Mill: Mill develops an argument from analogy: other bodies act as his body does when he experiences thoughts and feelings, so similar behaviour supports belief in similar inner causes. The argument makes other minds probable, but begins from a single directly known case — one's own.

A conclusion needs support from the stated reasons. Here, an extra linking premise is required before the consequence follows.

Whether a thinker is likeable does not establish whether their argument is sound. The reasons themselves must be assessed.

The portrait belongs to the named philosopher. Follow the profile link in the feedback to revisit their central move.

The portrait belongs to the named philosopher. Follow the profile link in the feedback to revisit their central move.

The first pair develops “Similar behaviour supports an analogy with my own mind.”; the second pair applies pressure from the rival position “Mental states are shown through meaningful behaviour.”.

The first pair develops “Mental states are shown through meaningful behaviour.”; the second pair applies pressure from the rival position “Conscious experience is private and irreducible.”.

The first pair develops “Conscious experience is private and irreducible.”; the second pair applies pressure from the rival position “Similar behaviour supports an analogy with my own mind.”.