What are we?

-Who are you?

+I am no one ,I am nobody.

-How can that be possible?

+You do not know who you are, or for that matter, where you are. You believe you are your body, your brain, your cells. But you are not. In fact, you are nothing. 

-How can I be nothing? I am me, and I am here. I am my body and my mind, I am my memories and wishes. You dare to tell me that I do not exist?

+Oh you do exist, but you do not know it, for you cannot know anything. Tell me, can something which is nothing, know anything. Can something that occupies no space, hold knowledge?

-It certainly cannot, yet I am something, for I can feel and think, and through centuries we have know that to be, is to think. I think, therefore I exist. That is for sure.

+I am not denying your existence, but clarifying that you are nobody, you are not your body. Your idea of being is wrong, since your essence is not held within the walls of your living corpse. 

-I do not understand. I am myself, my arms, my head, my bones. How can you deny that?

+I do. Tell me, if you take your arm out of your body, is that arm you? 

-It is definitely a part of me, but it is not me, as you affirm. 

+Then, if you could take your whole body out of your head, and you could contain your head in a vat and keep it alive, then, would that body be you, if you are still conscious in your head?

-It would not be me, just an old part of my self.

+Then take out your skull and skin, your muscles and veins, and replace every essential organ for artificial artifacts that maintain you alive. Would you be your skull or cheeks? 

-I would not. But, you are ruling out everything but my brain. Then, are you suggesting that all I am is my brain? A set of neurons? Is that your hypothesis?

+It is not. Let me finish, and you will see. Lately we have seen transistors behaving the same way as neurons. Lets now replace gradually each neuron with a transistor which performs its function flawlessly. If you replace one neuron, would  you still be your brain, or your brain and a transistor, or a transistor?

-Errrrrrrrr I do not know, it is confusing. I guess I would be both of them.

+Okay, now replace each neuron with a transistor. Would you still be your brain?

-No. 

+Would you be all transistors all together?

-I do not think so. I guess I might have ceased to be.

+Did you die?

-No. I just transformed.

+And, is transforming your mind destroying yourself, as you say? Since ceasing to be something means the destruction of that thing.

-I suppose.

+Then, when did you ceased to be you, and began being something else? When could we consider your old self apart from your new self? Where is the frontier between being a brain and being a chip?

-I guess something in the middle. In the transition between neurons and transistors is the limit, but I do not know where.

+Then, is it conceivable that, given the scenario where you can substitute neurons with transistors, with similar performance and no apparent output variation in thoughts, you were not your neurons at all in the first place?

-It is true. If I once considered myself my brain, and it was substituted with another structure, then I was never my brain in the first place.

+Now you see, you were not your body, nor your brain. Then what are you? Is your mind the combination of neurotransmitters firing at each moment? 

-I might be. But I am skeptical, and I refuse to believe that transistors could ever replace neurons.

+That is a fair point, since we cannot usually imagine what we have never experienced. But isn't it true that your only way of noticing anything in your body, is through nerves and neurons?

-It is true.

+Then, if you replace these nerves with other nano machines which perform similarly, there would be no way for you to notice a change, right?

-You speak the truth, but I still refuse to accept that machines could ever replace a cell.

+It is impossible at this epoch in time. Yet, there are artificial organs which save lives, and technology foresees advances at the cellular level in the next decades or centuries. So tell me, is it inconceivable that at some point in time, a machine could do the tasks of a cell, just as machines now do the tasks of men? 

-It is conceivable, yes.

+Then, assuming this premise, which though not necessary is still bearable, going back to the earlier issue, where are you, if you are not in your brain? Where are your thoughts, if not in your head?

-I do not know. Some people say there is a non material part of ourselves, called soul, which interacts with our material body.

+I agree that the latter might be a possibility. However, isn't it true that something composed of nothing, is, nothing? Isn't it true that love is literally no thing, nothing you can measure or touch, see or weigh, but just feel? Aren't all feelings nothing but something you feel with your immaterial  self, also called soul?

-They certainly are. But then, if we assume that our minds are non existent, and everything derived, such as thoughts and feelings, are too, what are they?

+That I do not know, but I can assure that anything non measurable, non detectable, in summary, anything without matter or at least, without a significant effect upon matter itself, belongs to the realm of the immaterial and of the mind, which in term is no thing. 

-I cannot deny that. 

+As for what follows from that, you are non material, you are nothing. 

-I don't care.