Process Reliabilism: An Externalist Theory of Justification

The Internal vs. External Divide

Before we dive into reliabilism, it's crucial to solidify the distinction between internalism and externalism.

Why would philosophers feel the need to look "outside the mind" for justification? Internalism, with its focus on conscious reflection, seems to struggle with a few common cases:

• Knowledge in Children (and Animals): A young child seems to know that the person in front of them is their mother. A dog seems to know the sound of its owner's car. Yet, it's unlikely they can articulate or reflect upon the reasons or evidence that justify these beliefs. Internalism seems to set the bar for justification too high for them.
• Unconscious Skills: Consider a "chicken sexer," a person trained to rapidly and accurately sort newborn chicks by gender. They are incredibly reliable (often over 99% accurate), but famously, they cannot explain how they do it. The cues are too subtle for conscious identification. Their belief about any given chick's sex seems justified, but they have no internal access to the justification.
• The Link to Truth: There's a strong intuition that a justified belief should be more likely to be true. Externalist theories aim to build this connection directly into the definition of justification, making it a matter of a belief's objective connection to reality.

These examples motivate the search for a theory where justification doesn't depend on a person's ability to perform complex self-reflection.

From a Causal Chain to a Reliable Process

One of the most influential externalist theories is process reliabilism, developed by philosopher Alvin Goldman. To understand it, it's helpful to see the theory it evolved from. Goldman's first attempt was a simpler idea called the "causal theory of knowledge."

The following video from Wireless Philosophy explains the causal theory and a famous thought experiment that revealed its critical flaw, paving the way for reliabilism.

Let's break down what we just saw:

• The Causal Theory proposed that you know something if your true belief is caused in an appropriate way by the fact itself. For example, you know there's a glass on the table because the glass reflects light, which causes a perception in your eyes, which causes you to form the belief.
• The Fake Barn County problem torpedoes this simple idea. Henry has a true belief ("that's a barn") that is directly caused by a real barn. The causal chain is perfect. However, our intuition is that he doesn't know it's a barn, because he is in an environment where his method of forming that belief (glancing from the road) is extremely unreliable. He was just lucky.

The key takeaway is this: the problem with Henry's belief isn't the causal chain, but the unreliability of the process he used in that specific context. This insight is the very foundation of reliabilism.

Defining Process Reliabilism

Process reliabilism proposes that:

A belief is justified if and only if it is formed by a reliable cognitive belief-forming process.

A reliable process is simply one that produces a high percentage of true beliefs.

• Reliable processes could include vision in good light, simple memory recall, and basic logical deduction.
• Unreliable processes would be things like wishful thinking, emotional reasoning, guessing, or vision in a thick fog.

Crucially, what makes reliabilism an externalist theory is that the believer doesn't need to know, or even have any beliefs about, the reliability of their process. All that matters for justification is the external fact that the process is reliable.

This next video explains this core externalist move very clearly.

This is a profound shift from what we've seen before. For an internalist (both foundationalists and coherentists), if you were challenged on a belief, you'd be expected to provide reasons or show how it fits with your other beliefs. For a reliabilist, the justification of your belief depends on objective facts about the process that produced it, whether you can access those facts or not.

Conclusion

Today, we've stepped outside the mind and into the world of externalist epistemology. We saw how problems with internalist accounts led philosophers to seek a different model of justification, one more directly tied to truth and capable of explaining knowledge in less sophisticated thinkers.

Key Takeaways:

• Externalism locates justification in factors that can be external to a believer's mind, such as the reliability of the cognitive process used.
• Process Reliabilism states that a belief is justified if it's the output of a reliable belief-forming process (one that tends to produce true beliefs).
• The key externalist feature of reliabilism is that the believer does not need to know that their process is reliable. It just has to be reliable.
• This approach helps explain knowledge in cases like young children or those with unconscious skills, but it faces challenges from thought experiments like "Norman the Clairvoyant," which suggest that we intuitively want some kind of internal awareness for a belief to feel truly justified.

Preview of the Next Lesson:
So far, we've looked at the structure of justification (foundationalism/coherentism) and the location of it (internal/external). In our next lesson, we'll shift our focus again, to a theory that is less concerned with individual beliefs and more with the person holding them. We will explore virtue epistemology, which asks: what are the intellectual character traits of a good thinker? This approach suggests that justification arises from the virtuous intellectual habits of the knower.