Background to the question:

The "philosophical zombie" or "p-zombie" is a thought experiment describing a hypothetical being that is in every way identical to a human being, except that it has no conscious experience. That is to say, this hypothetical person lives and behaves and interacts just like everyone else, but perhaps like a machine, there is no sentient first-person perspective experiencing each moment.

This concept is used to explore the implications of different philosophies about the nature of consciousness. Philosophers are split not so much about whether p-zombies exist, but whether the concept is theoretically possible in our universe. (I am not an expert on philosophy so forgive me if I have not understood or explained the topic accurately.)

I wonder if either side of this debate is compatible with Orthodox Jewish principles of faith. The way I see it there are three possibilities:

  1. Jewish thought broadly affirms the concept of a p-zombie as a possible reality
  2. The possibility of a p-zombie cannot be accepted, as it contradicts a basic premise of Jewish faith
  3. There is room for diversity of opinion on this issue

Ancillary to this issue, I wonder how the conscious experience within a human relates to Jewish perspectives on the neshamah and free will.

  • 1
    Related, possible duplicate: judaism.stackexchange.com/questions/132955/…. See comments for related links as well as discussion. If anything I said there interests you, feel free to ask. Or go there and ask one of the others in the discussion.
    – Rabbi Kaii
    Commented Mar 12, 2023 at 20:41
  • Possibly relevant Commented Mar 12, 2023 at 22:04
  • Judaism doesn't really spend a lot of time on these types of questions.
    – N.T.
    Commented Mar 13, 2023 at 2:53
  • In Judaism the notion of a p-zombie can be found in someone who lives in a projected personality.
    – The GRAPKE
    Commented Mar 13, 2023 at 9:12
  • @TheGRAPKE can you provide a reference for that statement? I am interested
    – Rabbi Kaii
    Commented Mar 16, 2023 at 17:52

1 Answer 1


The Torah makes much about our Free Will, and our uniquely G-d-like nature and potential behavior is framed by many of our sources in terms of that Free Will.

Can a Philosophical Zombie have free will? I think by most definitions, it can't. After all, free will means being able to take in one's thoughts as inputs, contemplate them, and decide an outcome. But a zombie has no "I" inside.

That "I" inside is the ruach memalela, the speaking spirit, that appears in Unqelus's translation of the creation of Adam in Bereishis 2:7. Not "only" a spirit that speaks to others, but one with an internal monolog. This is how the nishmas chayim (living soul) that Unqelus is translating is the same thing the gemara, the Zohar, and rabbis since associate with free will. (E.g. Seforno and Meshekh Chokhmah ad loc.) It being able to take its own thoughts back as input and make decisions about our decisions that we can even speak of having a "will".

Both via that internal monolog and through being aware of experiencing qualia.

(Experiencing qualia: A quale is the difference between a Mary the colorblind scientist knowing that a rose is red, and seeing a red rose and experiencing its redness. It is also the topic of the late-night chat in many dorm rooms, "How do I know that what I see when I see red isn't what you would call 'blue'?" In other words, since you cannot speak qualia, how do you know that both of us have the same quale for red? Anyway, back to to the show...)

Our ability to experience qualia is what Aristotle called "imagination". Not just limited to our current use of the word "imaginary", when we put together remembered qualia into something we didn't experience. And this idea enters the conversion of rishonim as "koach hadimyon" (the power or potential of being able to make likenesses). Rav Yisrael Salanter aligns seikhel (thought), the monolog, with the yeitzer hatov, and the koach hadimyon with the yeitzer hara, in the opening of his Igeres haMussar.

So, a zombie doesn't have a soul, it doesn't have an internal "I", neither the monolog nor the koach hadimyon necessary to be a ruach memalela, a being with free will.

Mal'akhim and sheidim could be zombie-esque. As we don't expect either to have free will. Intellects without free will might be zombies, or at least might have a theoretical zombie counterpart.

The other question would be whether it is possible to come up with the same behavior as a human being without free will. And without just saying Hashem makes sure to duplicate what the person's decision would have been had they have free will, since that isn't libertarian anyway.

And this is where I question the whole thought experiment. It presumes that just because we can imagine a brain can produce the same "outputs" / behaviors without consciousness, that such a thing is actually possible. I would argue it isn't.

For example, there are two ways to think through the question “Does an elephant have hair?”

The seikhel way of thinking: Elephants are mammals, all mammals have hair, and so unless elephants are the exception to the rule, they must have hair. Elephants are well known and discussed animals. Could they be an exception to the rule and I don’t know it? Nah, they must have hair

The koach hadimyon: I can remember elephants I saw, or that I saw pictures of. The detail may be blurry, so you may have to manipulate the picture a bit. Finally, a version of the picture which has a tuft of hair at the tail, maybe (if my memory is good) some downy hair around the eyes and ears, strikes me as the most familiar, the most real. And again I could reach the conclusion that elephants have hair.

To say that zombies are thing is to say that it is possible to make something that always reaches the same conclusions while working in tokens that represent ideas. That could work for simulating seikhel, but is it true that there are NO decisions rely koach hadimyon? In practice, we make many decisions only basedo on dimyon. R Yisrael Salanter says they tend to be bad ones; you need bicameral thinking to be healthy. ("Bekhol levavekha - bishnei yitzrakha / 'With your endire heart' -- with both yetzarim [good and evil]"?)

Every time we follow a desire, even a good one, we are following our mental image of what satisfying that desire would be like.

I simply don't think we can assume zombies could emulate that. So I don't think p-zombies could exist. But I don't think the Torah rules them out as much as straight logic does.

  • 1
    +1 for an excellent set of sources
    – Rabbi Kaii
    Commented Mar 16, 2023 at 14:52
  • Micha do you have an exact source/discussion associating the "I" with the ruach? If I "have" a ruach, then how can it be my I? Also, do you have any Torah sources that mention qualia? I am hugely interested
    – Rabbi Kaii
    Commented Mar 16, 2023 at 17:48
  • I spend about 6 weeks of shiurim showing how the Maharal and the Gra (and R Dessler) portray the Ruach as the "I" who emerges from the dialectic tension between the Nefesh and the Neshamah. I could collect quotes from the source sheets (see I-IV in the collection sefaria.org/collections/PisFzhfz?tab=sheets ), but you're asking a topic for a book, not a StachExchange comment. Commented Mar 16, 2023 at 18:50
  • Very reminiscent, from what little you've said, about the discussion between nefesh bahamis and nefesh elokis, mediated by the nefesh hasichlis. I wonder if there's a comparative study. Note, in that discussion, this I isn't "ultimate" - there's always a deeper etzem. Thanks so much for the sheet, I can't wait to delve into it when I have time, shkoyach
    – Rabbi Kaii
    Commented Mar 16, 2023 at 18:59
  • Are you saying that it's impossible to (in theory) to make a functionally identical replica of a human brain (replicating input/output behavior at let's say neuron excitation level, and not anything more detailed like quantum states, etc)? Because if it's possible to do so (which I'd assume it should be, the brain being a physical system), then that would be replicating/simulating anything and everything the brain does - seikhel, koach hadimyon, you name it. Would you call a person with this brain-replica a P-Zombie?
    – user9806
    Commented Mar 16, 2023 at 21:11

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