<div dir="ltr">I am curious if Brent was familiar with this passage from David Chalmer's "The Conscious Mind" (pages 267-268), which concern the plausibility of different qualia arising between two functional isomorphs made of different physical materials (e.g. silicon chips vs. neurons), and if so, what does this thought experiment imply for the role of molecules in the emergence of distinct quale?<div><br></div><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">“For the purposes of the illustration, let these systems be me and Bill. Where I have a red experience, Bill has a slightly different experience. We may as well suppose that Bill sees blue; perhaps his experience will be more similar to mine than that, but it makes no difference to the argument. The two systems are also different in that where there are neurons in some small region of my brain, there are silicon chips in Bill’s brain. This substitution of a silicon circuit for a neural circuit is the only physical difference between Bill and me.</span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">The crucial step in the thought experiment is to take a silicon circuit just like Bill’s and install it in my own head as a </span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-style:italic;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">backup circuit</span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">. This circuit will be functionally isomorphic to a circuit already present in my head. We equip the circuit with transducers and effectors so that it can interact with the rest of my brain, but we do not hook it up directly. Instead, we install a </span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-style:italic;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">switch</span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"> that can switch directly between the neural and silicon circuits. Upon flipping the switch, the neural circuit becomes irrelevant and the silicon circuit takes over. We can imagine that the switch controls the points of interface where the relevant circuits affect the rest of the brain. When it is switched, the connections from the neural circuit are pushed out of the way, and the silicon circuit's effectors are attached. (We can imagine that the transducers for both circuits are attached the entire time, so that the state of both circuits evolves appropriately, but so that only one circuit at a time is involved in the processing. We could also run a similar experiment where both transducers and effectors are disconnected, to ensure that the backup circuit is entirely isolated from the rest of the system. This would change a few details, but the moral would be the same.)</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">Immediately after flipping the switch, processing that was once performed by the neural circuit is now performed by the silicon circuit. The flow of control within the system has been redirected. However, my functional organization is exactly the same as it would have been if we had not flipped the switch. The only relevant difference between the two cases is the physical makeup of one circuit within the system. There is also a difference in the physical makeup of another “dangling” circuit, but this is irrelevant to the functional organization, as it plays no role in affecting other components of the system and directing behavior.</span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">What happens to my experience when we flip the switch? Before installing the circuit, I was experiencing red. After we install it but before we flip the switch, I will presumably still be experiencing red, as the only difference is the addition of a circuit that is not involved in processing in any way; for all the relevance it has to my processing, I might as well have eaten it. </span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-style:italic;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">After</span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"> flipping the switch, however, I am more or less the same person as Bill. The only difference between Bill and me now is that I have a causally irrelevant neural circuit dangling from the system (we might even imagine the circuit is destroyed when the switch is flipped). Bull, by hypothesis, was enjoying a blue experience. After the switch, then, I will have a blue experience too.</span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">What will happen, then, is that my experience will change “before my eyes.” Where I was once experiencing red, I will now experience blue. All of a sudden, I will have a </span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-style:italic;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">blue</span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"> experience of the apple on my desk. We can even imagine flipping the switch back and forth a number of times, so that the red and blue experiences “dance” before my eyes.</span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></p></span><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">This might seem reasonable at first–it is a strangely appealing image–but something very odd is going on here. My experiences are switching from red to blue, but </span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-style:italic;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">I do not notice any change</span><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">. Even as we flip the switch a number of times and my qualia dance back and forth, I will simply go about my business, noticing nothing unusual. By hypothesis, my functional organization after flipping the switch evolves just as it would have if the switch had not been flipped. There is no special difference in my behavioral dispositions. I am not suddenly disposed to say “Hmm! Something strange is going on!” There is no room for a sudden start, for an explanation, or even for a distraction of attention. Any unusual reaction would imply a functional difference between the two circuits, contrary to their stipulated isomorphism.”</span></p></span></blockquote><span id="gmail-docs-internal-guid-b364e282-7fff-3fb4-d7ad-67fb90b6ac50"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></p><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">Is there an error in this reasoning? If so, where is it?</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap"><br></span></p><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:11pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">Jason</span></p></span></div>