^There are now many versions of externalist theories. One of the simplest—known as process reliabilism—is both representative of
the main features of externalist views and is capable of explaining many of the features of knowledge that we seek to explain.
Theories of Knowledge LECTURE 5 externalist Theories of Knowledge
A simple version of a Gettier case comes from Bertrand Russell:
v Suppose you’re rushing to a meeting at noon in an unfamiliar building. You check the time on the clock in the hallway and it reads 11:55, so you believe that you have five minutes to get to the meeting location.
v Unbeknownst to you, however, the clock has stopped working hours before. Famously, though, even a stopped clock is right twice a day, and it just so happens that this clock stopped working exactly 12 hours ago, at 11:55 pm.
Here’s the problem: You believe it’s 11:55. It’s true that it’s 11:55. Your evidence for your belief is that the clock says it’s 11:55, and for all you know, you have no reason to suspect that the clock isn’t working. You’re even basing your belief appropriately on your evidence.
Most philosophers, however, agree that you don’t have knowledge in this case, because it’s purely an accident that your evidence points you toward the truth. Had you looked at the clock a few minutes earlier or later, it would still have read 11:55 and your belief would be mistaken.
Theories of Knowledge LECTURE 5 externalist Theories of Knowledge
^One of the earliest statements of process reliabilism can be found in the work of mathematician F. P. Ramsey, who wrote in a 1929 paper,
b
I have always said that a belief was knowledge if it was (i) true, (ii) certain, and (iii) obtained by a reliable process.^With the exception of the inclusion of what Ramsey terms “certainty,”
this account of knowledge is very similar to ones that we would encounter today.
^If we reformulate the account to make it compatible with fallibilism, we’re left with this: Knowledge is true belief on the basis of a reliable process.
Here, the term “reliable” roughly means “consistent.” And a “reliable process” is a process that reliably results in true beliefs.
P sychologists use the term “reliability” roughly to mean “consistency.” In psychology, a measure is reliable if, given the same inputs, it’ll yield the same outputs.
For psychologists, then, something could be reliable but wrong—as long as it’s wrong consistently. For example, if your watch is running well but is set 23 minutes fast, then your watch is reliable, despite not being accurate.
When psychologists talk about the accuracy of a measure, they use the term “validity.” So, for a psychologist, the best measures would be those that are both reliable and valid.
It’s this that philosophers are aiming at with the notion of “reliable process.”
Theories of Knowledge LECTURE 5 externalist Theories of Knowledge
^It’s obvious how the process reliabilist theory can answer the first challenge—the challenge of explaining the basing relation.
According to the process reliabilist, knowledge is true belief formed on the basis of a reliable process, a process that reliably yields true beliefs. And the answer to the question of how to determine the basing relation is baked right into the reliabilist theory:
A belief that counts as knowledge will be appropriately based on the grounds that justify it because what it is for a belief to be justified is precisely to be caused by a process that reliably yields true beliefs.
^With regard to the second
challenge—that of the Gettier cases—
we need to consider the notion of
“reliable process.” Note that in order to think about reliability accurately, we’ll have to suppose that we’re considering a process to be reliable with respect to a certain environment.
This is important, because processes that are reliable with respect to one environment may not be reliable with respect to a different environment.
^Consider a car whose engine is designed to function properly on generally well-paved roads in an industrialized nation. In a different environment—for example, in a desert with few roads—the engine might clog and become useless.
The fact that the car’s engine
environments does not mean that it isn’t reliable, but rather that it’s only reliable in the environments for which it was designed to function.
^So, our account of knowledge in terms of reliable processes would have to include a reference to the environment as well. We could, more properly, say something like this:
Knowledge is true belief based on a process that is reliable (in the sort of environment in which that belief was produced).
^The challenge is to come up with an account of justified true belief that explains why Gettier cases—such as the stopped clock—are not cases of knowledge. And the process reliabilist theory allows us to do just this.
^Even though we have a true belief in the clock case, we don’t have knowledge. The reason for this is that the process we’ve used—looking at a clock in the vicinity and relying on the information it conveys—is unreliable in an environment where the clock in the vicinity has stopped.
^For the process reliabilist, someone who believes on the basis of an unreliable process is not justified. We have a true belief, but no justification.
And without justification, there is no knowledge. So, the process reliabilist can explain why Gettier cases aren’t cases of knowledge.
Theories of Knowledge LECTURE 5 externalist Theories of Knowledge