Clark and Chalmers’s Vehicle Externalism
Vehicle externalism is an approach to the mind with a broader scope than that of content externalism. One starting point for explaining vehicle externalism is Andrew Clark and David Chalmers’s article “The Extended Mind” (Clark and Chalmers 1998), wherein they ask us to consider a rotation task, such as the following, where you rotate the top shape to see if it fits in the bottom shape:
How do we perform this task? The standard account is that we perform inner mental rotations—simulations to see how things fit.
Imagine doing the same rotation with a computer. You see the figures on a monitor and rotate the top one, using a keyboard. Have you played Tetris? Then you know how this works. If you can do this sort of rotation both in your head and on the computer, then why should we say that only the internal rotation is mental? When you rotate the figure on the computer, aren’t you engaged in a mental process as well? Couldn’t we say that the mental processes involved are distributed over the tools you use? Couldn’t we say that the rotation takes place across you and the computer? Clark and Chalmers argue that you and the computer form a coupled system that, as a whole, performs the rotation. They also ask you to consider a variant of the rotation task, where you rotate the figure on the screen through a brain implant.
Their intuition is that this is a cognitive system that spans across the computer and your brain; you are coupled so tightly and transparently to the computer that you form a single cognitive system—you just think the rotation, and it happens. They also believe there is little difference between the second and third case. You might be using a keyboard in the second case instead of an implant, but all the same, the cognitive processes span across you and the computer in a coupled system.