Why you are not a Brain in a Vat

Scepticism Philosophy Science 2 min read

Have you every been tormented by the thought you might be a brain in a vat? Worry no longer! Read on to get peace of mind in under 2 minutes.

By Gaetan Lee . Tilt corrected by Kaldari. - originally posted to Flickr as Chimp Brain in a jar, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=28819747
Stuck in a bad place.

My best friend is a robot

The traditional brain in a vat argument runs something like:

  1. Your sensory 'data' is a set of inputs into your brain (or nervous system)
  2. From what Neuroscience teaches us (etc, etc) we 'know' that this information is in the form of stimuli to neurons
  3. This could be simulated in a 'vat' like situation
  4. It would be impossible to know the difference in the situations, as the sensory inputs which your brain processes would be the same
  5. Hence, you don't know whether your brain is in a vat or not.

Uh-oh. You don't want that late night cuddle with your spouse to have been merely an electrical current running through some vat, matrix style. Frankly, none of that seems very appealing at all for any interaction you have.

That's impossible because I don't like it

The issue with any response to the thought experiment is that, if we are just a brain with certain electrical impulses, there is no reason why it is not possible those impulses are simulated.

Perhaps you question the motives of whomever it is who put your brain in a vat. You say that this is implausible. Yet - implausible compared to what exactly? Implausible in your computer-generated experiences? For it to be implausible assumes you have a suitable reference point to know what is plausible.

You might even begin to think that someone who creates arguments to counter the brain in vat thought experiment is motivated by avoiding uncomfortable ideas, rather than by finding the truth.

And you? What are your motivations

Hey, I was once a Solipsist. So, I guess I get a free pass on those suspicions.

Don't be impulsive!

Yet the brain in vat hypothesis is flawed.

Let us review the argument. It argues that our sensory data is dependent on inputs which can be replicated. This view is not a priori obvious. I mean, we experience the world, and we don't immediately think of neurons firing and electrical impulses. In fact, this view is based on empirical (i.e. Scientific) observations, and hence on experimentation. For these observations and theories to carry weight, the experimental data must be valid.

However, if Scientific theory then implies that our observations are not reliable because they are not necessarily (mostly accurate) representations of the world and we don't know if that data has been falsified that then undermines the empirical data was originally based off. I.e. experiment-based evidence cannot be used to support a thesis which then implies the experiments had no validity.

Perhaps you are a bran flake, or a coco pop

This may not be satisfying for the moment. But thinking you are a brain in a vat is incoherent. For now, it remains just as likely you are a coco pop (a yummy chocolate breakfast cereal) or a bran flake (a weird cereal for healthy people) than a brain in a vat.

Descartes' demons?

Q: Is a demon tormenting me? Ya'know, I've read some Descartes.

A: Well aren't you a sceptical bunny.

Watch this space. I am going to do more pieces combating more difficult cases of Philosophical Scepticism soon!

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