Answering Is this a good argument against mental causation? led me to a simple metaphysical question, and I wonder if anyone in the Western Canon addressed it, particularly someone in the last century.

Consider that Elon Musk's company Neuralink has been approved for field trials by the FDA. At some point in the not too distant future, we may have partial access to each other's thoughts.

If one admits brain-to-brain or telepathic communication into one's mental ontology, are there profound ramifications for reorganizing the philosophical canon? Has this been discussed in the literature?

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    For philosophical discussions from different perspectives, see Cochrane, A case of shared consciousness and Egnor, The Craniopagus Twins and Thomistic Dualism.
    – Conifold
    Commented Sep 9, 2023 at 17:27
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    @Conifold, clearly with conjoined twins who have somewhat conjoined brains, it becomes somewhat unjustified to treat them as two individuals in the conventional sense.
    – Steve
    Commented Sep 9, 2023 at 17:29
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    @Steve As you can see from the links, the consensus is that they are two separate individuals. Not just among philosophers, psychologists who work with them concur. Other twins were even surgically separated.
    – Conifold
    Commented Sep 9, 2023 at 17:43
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    @Conifold, but there's clearly no physical reality to that separation. The matter we typically consider as comprising the brain and the seat of cognitive activity, in their case is seen to be a single undivided mass. I'm not doubting that some functions of each "half" of the brain may be independent (that is, no more dependent than two unjoined individuals), but clearly also some functions are performed (or sensory facilities shared) by the conjoined total in a way that doesn't localise to a particular "half".
    – Steve
    Commented Sep 9, 2023 at 18:01
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    @Conifold, what I've read suggests that (speaking in terms of a conventional body plan) both twins have shared control of some of each other's limbs, receive inputs from three or all four eyes, from touch over each other's bodies, from tastes in each others mouths, have some ability to internally communicate or share thoughts (unclear whether this sharing has to be done wilfully, or whether the inspection can occur regardless of the other's will), and tend to share moods. If that is merely "minor", it's hard to imagine what could be regarded as major.
    – Steve
    Commented Sep 9, 2023 at 20:44

3 Answers 3


This poses an interesting question. Philosophy has long grappled with the ineffable—those aspects of human experience and existence that seem beyond the reach of language. With brain-to-brain communication, the potential exists to bypass the inherent limitations of words and convey complex, subjective experiences directly. This development should at a minimum encourage philosophers to reconsider the boundaries of what can be expressed and understood (acquisition of knowledge) through traditional language.

The introduction of a direct mind-to-mind connection may challenge traditional epistemological frameworks. Questions about the nature of knowledge, belief, and understanding take on new dimensions when thoughts can be shared without linguistic mediation. Philosophers may need to reassess the criteria for valid knowledge and explore how this impacts our understanding of truth and justification

The direct transmission of thoughts could lead to profound existential and metaphysical questions. For example, the concept of solipsism (the idea that only one's mind is certain to exist) might take on renewed significance. Philosophers would explore the implications of this technology for our understanding of reality, existence, and the nature of the self.

I hope this accurately pinpoints some of the potential considerations that brain to brain communication may pose. Thanks for the fun idea!

--- Some bored philosophy student



What exactly do we mean by "brain-to-brain communication"?

I can already communicate with other brains in a variety of ways - speech, signs, demeanour, and so on.

Even if there were a new mode of communication discovered - whether telepathy or a thought-reading machine - I shouldn't think it would need any overhaul of philosophy, since the essential fact of communication is already acknowledged.

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    I disagree. The neurons in your brain communicate with each other all the time, but they are not individuals. If we were to directly communicate with each other's neurons, then we would have to ask ourselves what an individual actually is. Where does one person start and another end? You can normally hide thoughts from others by not articulating them, but you would not have any way of doing that if other people had direct access to your neurons. Commented Sep 11, 2023 at 7:42
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    @EmilKarlsson, they are only "not individuals" because we arbitrarily declare certain things to belong to the individual (or to be an individual) and certain things not to. The division under normal circumstances is never that firm - people chatter and exchange ideas constantly - so no competent philosophy would be disrupted merely by new means of exchange. Even in terms of breaking the supposed privacy of the mind, individuals are not generally that successful at concealing their thinking from others over a period of time.
    – Steve
    Commented Sep 11, 2023 at 10:18
  • This doesn't survive a typical cross-species test.
    – Corbin
    Commented Sep 11, 2023 at 19:54

Has brain-to-brain communication been addressed in the literature, and if so, is there a fundamental reorganization of philosophy required?

There is not a fundamental reorganization of philosophy required because it does not necessarily resolve various philosophical matters, such as those in the philosophy of mind.

The topic of solipsism may involve discussion of brain-to-brain communication in that you can still be skeptical that there is another brain that you are communicating with.

Brain-to-brain communication may expand on the topic of the hivemind in relation to philosophy of mind.

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