4 ms·

Direct Realism and the Brain-in-a-Vat Argument

18 points by hn-0001 4y ago

benlivengood 4y ago
> We have no strong, independent reason for preferring the Real World Hypothesis over the BIV Hypothesis. Except that drugs and blunt trauma have direct impact on our experience. So a BIV would need some additional poking and prodding to mimic what would happen to the simulated brain. What happened to BIV's who got simulated lobotomies, for example? And if we posit that the simulation adjusts the actual brain in the vat accordingly then it becomes the general full-simulation argument, not BIV.
- yayachiken 4y ago
  You need to go deeper. What you are describing is not really what the BIV scenario is about. Modelling the BIV directly after the brains we know only serves as a justification in the thought-experiment that a BIV might reasonably exist. But actually the BIV does not need to be of similar character or composition than the simulated brains that a BIV can observe in its observable simulated world. Even if a simulated lobotomy would be performed under simulated general anesthesia, there is no reason to assume that the BIV itself would be completely inert during that time, the consciousness might well be a compartment of the BIV with other compartments tracking e.g. changes in the simulated body. This is not yet a full-simulation argument as the individuum itself is not yet part of the simulated universe, the simulation is still an external stimulus to the BIV system. The important takeaway here is that in a fully simulated universe, the concept of an objective "reality" is still intact, and generalized to nested realities. With a BIV, the perceived reality is always required to be entirely subjective. If the stimulus machine of a BIV is turned off, the individuum is still intact (and probably still wondering what the hell happened as it's suddenly floating in unperceivable nothingness), if a full-simulation is turned off, all observers (except those in the "higher" reality) cease to exist immediately.
  - benlivengood 4y ago
    To be accurate a BIV would have to be able to reproduce any physical effect that could operate on the simulated brain. Regardless of what the BIV is implemented in (could be computronium or spiritual stuff) the QCD field theory still applies to effects the BIV would have to (for lack of a better word) simulate. We routinely use gamma knives and fMRI on brains as well as more traditional surgery tools, and astronauts "see" cosmic ray interactions. It matters where exactly those cosmic ray or gamma interactions happen with brain molecules, and so regardless of BIV substrate I'd argue strongly that the BIV must simulate a physical human brain to be accurate. Maybe I'm not supposed to take the premise that human brains can exist as QCD-physical objects? In that case it seems more like the dualistic belief that a spirit or supernatural entity puppets the physical body around and interprets its interactions with the physical world. (Which runs into the same problem of dramatic effects physical changes to brains have) So in the example of turning off the simulation and leaving the BIV running you either turn off the effects of receiving oxygen through the bloodstream in the same way choking or drowning produces, or you break the simulation of reality to artificially keep the BIV running despite conditions that would have stopped it if the simulated brain was removed from the simulated body accurately. How does disconnecting a BIV work, precisely, when e.g. homeostasis is enough to produce varying effects on conscious experience? Neurons get tired after firing and require nutrients to recharge. Those nutrients exist in the physical/simulated world and if they behaved even slightly differently the neural firing patterns would differ and the BIV and physical human brain would diverge. When the simulated nutrients go away does the BIV just pretend a baseline digestive, endocrine, cardiovascular, and lymphatic system still exist and fake everything? If so, then the BIV doesn't exist without regard to the turned-off simulation, it gets copy-pasted into a simplified simulation of whatever minimal physical apparatus would keep a physical human brain alive in a jar.
    - mannykannot 4y ago
      > To be accurate a BIV would have to be... The thing is, though, there is no requirement for it to be accurate, it merely has to be fed simulated stimuli that are consistent enough that the mind of the BIV does not deduce the reality of its situation. For example, the simulation of banging one's head against a wall could be somewhat or even quite inaccurate without the BIV being able to tell that it is, even if it chooses to bang its simulated head against a simulated wall.
robbedpeter 4y ago
We are brains in vats. Bone vats. Supported by complex biomechanical, electrical, and chemical systems that convert food to chemical energy and filter waste for the brain. So is the important part of the question whether reality is being modified by a man in the middle? You end up exactly where you are already, having to answer the same questions about where you are in Plato's cave, so unless you have evidence to think you're in a simulation, the simplest explanation is that there's no filter between you and reality except the limits of your senses and cognitive capacity. This is the same argument about living in the matrix. You can't assume that the option of us not being brains in vats is available. You'd have to explain what a brain not in a vat would look like - something entirely made of computronium, in a configuration radically different than our hodgepodge evolved meat suits look like. It's more likely that we're simulated and tricked to think we have brains and bodies than for us to be physically different, and stuck in a Matrix all unaware. I'll stick with the simplest explanation that satisfies all available evidence. We're all brains in bone vats riding around meat suits for adventure and exploration.
nootropicat 4y ago

18 points by hn-0001 4y ago

> We have no strong, independent reason for preferring the Real World Hypothesis over the BIV Hypothesis. Except that drugs and blunt trauma have direct impact on our experience. So a BIV would need some additional poking and prodding to mimic what would happen to the simulated brain. What happened to BIV's who got simulated lobotomies, for example? And if we posit that the simulation adjusts the actual brain in the vat accordingly then it becomes the general full-simulation argument, not BIV.

yayachiken 4y ago
You need to go deeper. What you are describing is not really what the BIV scenario is about. Modelling the BIV directly after the brains we know only serves as a justification in the thought-experiment that a BIV might reasonably exist. But actually the BIV does not need to be of similar character or composition than the simulated brains that a BIV can observe in its observable simulated world. Even if a simulated lobotomy would be performed under simulated general anesthesia, there is no reason to assume that the BIV itself would be completely inert during that time, the consciousness might well be a compartment of the BIV with other compartments tracking e.g. changes in the simulated body. This is not yet a full-simulation argument as the individuum itself is not yet part of the simulated universe, the simulation is still an external stimulus to the BIV system. The important takeaway here is that in a fully simulated universe, the concept of an objective "reality" is still intact, and generalized to nested realities. With a BIV, the perceived reality is always required to be entirely subjective. If the stimulus machine of a BIV is turned off, the individuum is still intact (and probably still wondering what the hell happened as it's suddenly floating in unperceivable nothingness), if a full-simulation is turned off, all observers (except those in the "higher" reality) cease to exist immediately.
- benlivengood 4y ago
  To be accurate a BIV would have to be able to reproduce any physical effect that could operate on the simulated brain. Regardless of what the BIV is implemented in (could be computronium or spiritual stuff) the QCD field theory still applies to effects the BIV would have to (for lack of a better word) simulate. We routinely use gamma knives and fMRI on brains as well as more traditional surgery tools, and astronauts "see" cosmic ray interactions. It matters where exactly those cosmic ray or gamma interactions happen with brain molecules, and so regardless of BIV substrate I'd argue strongly that the BIV must simulate a physical human brain to be accurate. Maybe I'm not supposed to take the premise that human brains can exist as QCD-physical objects? In that case it seems more like the dualistic belief that a spirit or supernatural entity puppets the physical body around and interprets its interactions with the physical world. (Which runs into the same problem of dramatic effects physical changes to brains have) So in the example of turning off the simulation and leaving the BIV running you either turn off the effects of receiving oxygen through the bloodstream in the same way choking or drowning produces, or you break the simulation of reality to artificially keep the BIV running despite conditions that would have stopped it if the simulated brain was removed from the simulated body accurately. How does disconnecting a BIV work, precisely, when e.g. homeostasis is enough to produce varying effects on conscious experience? Neurons get tired after firing and require nutrients to recharge. Those nutrients exist in the physical/simulated world and if they behaved even slightly differently the neural firing patterns would differ and the BIV and physical human brain would diverge. When the simulated nutrients go away does the BIV just pretend a baseline digestive, endocrine, cardiovascular, and lymphatic system still exist and fake everything? If so, then the BIV doesn't exist without regard to the turned-off simulation, it gets copy-pasted into a simplified simulation of whatever minimal physical apparatus would keep a physical human brain alive in a jar.
  - mannykannot 4y ago
    > To be accurate a BIV would have to be... The thing is, though, there is no requirement for it to be accurate, it merely has to be fed simulated stimuli that are consistent enough that the mind of the BIV does not deduce the reality of its situation. For example, the simulation of banging one's head against a wall could be somewhat or even quite inaccurate without the BIV being able to tell that it is, even if it chooses to bang its simulated head against a simulated wall.

robbedpeter 4y ago

We are brains in vats. Bone vats. Supported by complex biomechanical, electrical, and chemical systems that convert food to chemical energy and filter waste for the brain. So is the important part of the question whether reality is being modified by a man in the middle? You end up exactly where you are already, having to answer the same questions about where you are in Plato's cave, so unless you have evidence to think you're in a simulation, the simplest explanation is that there's no filter between you and reality except the limits of your senses and cognitive capacity. This is the same argument about living in the matrix. You can't assume that the option of us not being brains in vats is available. You'd have to explain what a brain not in a vat would look like - something entirely made of computronium, in a configuration radically different than our hodgepodge evolved meat suits look like. It's more likely that we're simulated and tricked to think we have brains and bodies than for us to be physically different, and stuck in a Matrix all unaware. I'll stick with the simplest explanation that satisfies all available evidence. We're all brains in bone vats riding around meat suits for adventure and exploration.

nootropicat 4y ago