Conclusion

In this chapter, we have discussed some of the central questions of epistemology. Starting with the question how we know that we aren't just brains in a vat, the playthings of an unscrupulous scien­tist, we were led to ask what knowledge is.

Finally, we tried a radical way out. We gave up the idea that our theory of justification needed to be phenomenological. The result­ant theory is that in order to know S,

a) you must believe S,

b) S must be true, and

c)     your belief in S must be caused in a way that is reliable in the circumstances.

This theory allows us to claim to know that we aren't brains in a vat even though our experiences could be the very same if we were brains in a vat. It also provides us with a reason for caring about whether other people's true beliefs are knowledge, for we have an interest in the reliability of the processes by which beliefs are acquired. If someone has a lot of knowledge about a certain subject matter, then he or she forms beliefs reliably. And that means we have a reason to rely on that person in the future.

The dispute between causal theory and traditional epistemology is a dispute between a theory that regards minds as causal systems in the world, on the one hand, and a theory that regards minds from the point of view of the individual “looking out” on the world, on the other. In this respect it is like the dispute between phenomenologist and functionalist that we discussed at the end of the last chapter. Just as Descartes is on the same side—against the “objective” view of mind—in both these disputes, so many philosophers who are functionalists are on the objective side in epistemology. To see mind and knowledge in the way the functionalist and the causal episte- mologist do—as a causal system in the world—is to support a form of naturalism. It is to see human beings with their philosophical problems as part of the wider world of nature, not as privileged observers somehow outside that natural world.