Brains In Vats Essay

Is “We are brains in a vat” always false?

One form of skepticism is the skepticism about the external world — the theory that we can never have any knowledge about the external world, even the existence of it; the theory also suggests that we can only know the internal world which is our own mind(Carr, lecture 8). For example, a skeptic may say “we don’t know if we have hands because what we see may be illusions” or “we don’t know if we are not brains in vats experiencing a huge hallucination”. Among many philosophers who attempt to defeat skepticism about the external world, Putnam argues that “we are brains in vats”(BIVs) is always self-falsifying because brains in vats do not satisfy the necessary condition for being able to refer to the

Although Putnam’s argument successfully defeats one version of BIV, it does not defeat all versions of BIV. In this paper, I will explain Putnam’s BIV scenario and his semantic arguments against skepticism about the external world; Specifically, I will give one version of BIV that is not affected by Putnam’s argument; I will argue that my version of BIV not only successfully makes Putnam’s argument flawed but also could not be dismissed easily.

I will begin by explaining the BIV scenario Putnam considers. Imagine that an evil scientist(or a machine, or something powerful but unnameable but let’s call it “an evil scientist”) captures a person, removes his brain from his body, and puts it in a vat with all of its nerve endings connected to a supercomputer which stimulates reality - the disembodied brain has perfectly normal conscious

Putnam says that if we are people in the possible world - we are all brains in vats connected to a supercomputer, we wouldn’t be able to refer to the actual brains in a vat when we think or say “we are brains in vats” at all. First, I want to explain the semantic(linguistic related) point behind this objection. Let’s consider the scenario that there are two places called “OASIS” in San Diego. One is the department in UC San Diego where you can get help with writing, and the other one is the game center in downtown San Diego. Suppose that I only know the academic department and I’ve never heard of the game center at all and my friend, who has never known the existence of the academic department, always love to go to the game center downtown. When we meet up and say “let’s go to OASIS!”, we are referring to two different places and by no means could I ever think or refer to the game center because I’m not causally connected to it at all. The English acronym “OASIS” is not causally connected to the game center or the academic department, as well. It follows Putnam’s “causal constraint” that in order to refer to (or have mental states about) X, a person needs to have the appropriate causal connections to X(Carr, lecture 8). Now I will explain how Putnam uses the “causal constraint” to reject the BIV scenario he considers. Notably, by hypothesis of the scenario, brains in vats don’t have any knowledge of the external world and the external