# Mainstream Epistemology for LessWrong, Part 1: Feldman on Evidentialism

Richard Feldman's _[Epistemology](http://www.amazon.com/Epistemology-Richard-Feldman/dp/0133416453)_ is a widely-used philosophy textbook published in 2003. I've decided to write a series of posts summarizing its contents, because it contains some surprisingly reasonable views (given what you may have heard about mainstream philosophy), and it also counters some common myths about what all philosophers supposedly know about evidence, the problem of induction, and so on. This installment briefly covers the first three chapters before moving on to Feldman's discussion of the philosophical view he calls evidentialism.

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Chapter 1 is an introductory chapter, which explains that "The theory of knowledge, or epistemology, is the branch of philosophy that addresses philosophical questions about knowledge and rationality." Feldman says he will use the term "The Standard View" to refer to the collection of things we ordinarily think about knowledge and rationality.

On the Standard View, we know a large variety of things about a variety of topics, from science and mathematics to other people's mental states to the past and the future. Furthermore, the Standard View says that our primary sources of knowledge consist of perception, memory, testimony, introspection, reasoning, and rational insight. Those are just the sources of knowledge most people would agree on, though—Feldman acknowledges that some people might want to add to that list.

It's worth mentioning here that because [philosophers agree on so little](/lw/iu0/trusting_expert_consensus/), **when you read a philosophy textbook you should assume it will say some things that are just the author's personal opinion, rather than representing any professional consensus**. And in describing the "Standard View," Feldman is mostly just trying to describe what ordinary people commonsensically believe, rather than claiming that it's the standard view within philosophy. But in fact, most philosophers probably would agree with what Feldman calls the "Standard View."

Chapter 1 also sketches the structure of the rest of the book: chapters 2-5 will develop the Standard View, while chapters 6-9 will consider various challenges and objections to the Standard View.

I'm going to mostly skip over chapters 2 and 3 because they cover a debate that was pretty accurately summarized by Luke Muelhlauser and Louie Helm in ["Intelligence Explosion: Machine Ethics"](https://intelligence.org/files/IE-ME.pdf):

> Since Plato, many have believed that knowledge is justified true belief. Gettier ([1963](http://www.ditext.com/gettier/gettier.html)) argued that knowledge cannot be justified true belief because there are hypothetical cases of justified true belief that we intuitively would not count as knowledge. Since then, each newly proposed conceptual analysis of knowledge has been met with novel counterexamples (Shope 1983). Weatherson (2003) called this the “analysis of knowledge merry go round.”

That said, it's worth briefly explaining Feldman's own solution to the problem, which will be relevant for understanding chapter 4. With rare exceptions, philosophers generally agree that true belief is necessary, but not sufficient, for knowledge. The question is how to replace or supplement the justification condition. Feldman's answer is to keep the justification condition, and furthermore add that knowledge requires that ones justification for a belief "does not essentially depend on any falsehood." (If you click the link to Gettier's paper, above, and read Gettier's examples, hopefully you will understand why this is appealing.)

Feldman includes a disclaimer saying, "The idea of essential dependence is admittedly not completely clear. However, it gives us a useful working definition of knowledge with which we can proceed." Being willing to invoke a somewhat unclear condition in his analysis of knowledge is probably a wise move on Feldman's part, given the history of attempts at more exact analyses being felled by clever counterexamples. And his analysis gives him a rationale for focusing on the next chapter on what it takes for a belief to be justified.

Chapter 4 is dedicated to discussing evidentialism, which Feldman defines as the view that a belief is justified for a particular person if and only if their evidence supports that belief. This is a view Feldman has defended in a number of journal articles, many of them co-authored with Earl Conee (see their anthology, _[Evidentialism](http://www.amazon.com/Evidentialism-Earl-Conee/dp/0199253730)_). That this view has defenders within mainstream philosophy may surprise those who've heard that there's supposed to be a philosophical consensus that requiring beliefs to be based on evidence is self-defeating (no such consensus exists, but [some](http://www.patheos.com/blogs/hallq/2013/11/the-plantinga-clique/) [philosophers](/lw/j09/academic_cliques/) [claim it does](http://www.patheos.com/blogs/hallq/2013/11/paper-on-plantinga-and-classical-foundationalism/)).

Feldman emphasizes that evidentialism, in the form he defends, is an epistemological claim, not a moral or prudential one. He's not interested in defending the claim, found in William Clifford's famous essay ["The Ethics of Belief,"](http://www.infidels.org/library/historical/w_k_clifford/ethics_of_belief.html) that "it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence" (at least, not if the claim is taken to be a moral one).

This is how Feldman responds to the "loyalty" objection to evidentialism, which argues that it is sometimes right to, for example, believe in a friend's innocence even when the evidence does not support that conclusion. Feldman allows that that _might_ be right as a matter of morality (he doesn't say it _is_ right), but says that doesn't change what the rational thing to believe in such a case is.

The rest of the chapter is a fairly long (given that book as whole is only 200 pages) discussion of the infinite regress argument, foundationalism, and coherentism. It's worth interjecting that, while Feldman presents the discussion not in terms of objections to evidentialism, but in terms of "ways in which the details of evidentialism might be spelled out," some philosophers have claimed the infinite regress argument as an argument for radical skepticism, while others have claimed it shows (as a matter of philosophical consensus!) that evidentialism specifically leads to radical skepticism.

Feldman's discussion could be read as a gentle rebuttal to these claims, even though he never addresses them directly. His version of the infinite regress argument is formulated as an argument for the existence of justified basic beliefs, which he defines as beliefs that are justified, but "not justified on the basis of any other beliefs." It runs as follows:

1.  Either there  are justified basic beliefs or each justified belief has an evidential chain that either: (a) terminates in an unjustified belief (b) is an infinite regress of beliefs (c) is circular.
2.  But beliefs based on unjustified beliefs are not themselves justified, so no justified belief could have an evidential chain that terminates in an unjustified belief (that is, not (a)).
3.  No person could have an infinite series of basic beliefs, so no justified belief could have an evidential chain that is an infinite regress of beliefs (that is, not (b)).
4.  No belief could be justified by itself, so no justified belief could have an evidential chain that is circular (that is, not (c)).
5.  Therefore, there are justified basic beliefs.

Feldman lists three main responses to this argument: foundationalism, which accepts the argument's conclusion; coherentism, which rejects premise 4; and skepticism, which says the argument goes wrong assuming that there _are_ justified beliefs in the first place and in fact no beliefs can be justified. In this chapter, Feldman's focuses on foundationalism and coherentism, leaving skepticism for later chapters.

First, he considers a view he calls "Cartesian foundationalism," named after René Descartes, though Feldman admits "that it is unlikely that Descartes actually would agree to all aspects of the view to be described." Cartesian foundationalism, in Feldman's sense, combines foundationalism with three further claims:

1.  Beliefs about one's own inner states of mind (appearance beliefs) and beliefs about elementary truths of logic are justified basic beliefs.
2.  Justified basic beliefs are justified because we cannot be mistaken about them. We are "infallible" about such matters.
3.  The rest of our justified beliefs (e.g., our beliefs about the external world) are justified because they can be deducded from our basic beliefs.

People who know something of Descartes' reputation within contemporary philosophy will not be surprised to find out that Feldman sees lots of problems with this view, including that our beliefs about our own inner states of mind _aren't_ infallible, and that much of what what we know cannot be deduced from beliefs about our own inner states of mind.

Next, Feldman discusses coherentism. The challenge for coherentism is developing it in a way that doesn't involve obvious circularity. As Feldman explains:

> So coherentists reject premise (1-4) of _The Infinite Regress Argument,_ the step of the regress argument that rejects circular evidential chains. This is not because they think that you can justify one belief by another, that second by a third, and then justify the third by appeal to the first. Rather, their idea is that justification is a more systematic and holistic matter, that each belief is justified by the way it fits into one's overall system of beliefs.

Feldman discusses various ways to develop this idea, but doesn't find any "suitable," because among other things of difficulties with giving a coherentist account of which beliefs are and are not justified, and with saying what coherence actually is. He also discusses the "isolation argument" against coherentism, which complains that coherentism seems to allow any beliefs to be justified when included in the right set of other beliefs, even if the whole set of beliefs is totally detached from reality. The point is that what matters for beliefs being justified isn't just other beliefs, but also things like our sensory experiences.

Finally, Feldman discusses his own preferred view, which he calls "modest foundationalism," which claims:

1.  Basic beliefs are spontaneously formed beliefs. Typically, beliefs about the external world, including beliefs about the kinds of objects experienced or their sensory qualities, are justified and basic. Beliefs about mental states can also be justified and basic.
2.  A spontaneously formed belief is justified provided it is a proper response to experiences and is not defeated by other evidence the believer has.
3.  Nonbasic beliefs are justified when they are supported by strong inductive inferences—including enumerative induction and inferences to the best explanation—from justified basic beliefs.

The main objection Feldman discusses to this view comes from a coherentist angle: Laurence BonJour's argument that there are _no_ justified basic beliefs. The details of that discussion, though, are less interesting than this simple fact: the suggestion made by some anti-evidentialist philosophers that evidentialism is indisputably self-defeating is just plain wrong. The idea seems to be based on equating "basic belief" with "belief not based on evidence." That would seem to allow the infinite regress argument to be turned against evidentialism.

However, this ignores the fact that Feldman (or someone with similar views) would argue that basic beliefs are supported by evidence to the extent that they're a proper response to experience and not defeated by other evidence. Furthermore, many people would reject other premises of the "infinite regress argument against evidentialism," particularly coherentists rejecting premise 4. This by itself doesn't prove that evidentialism is true. It could still be wrong for other reasons. But at the very least, the case against it is nowhere near as clear-cut as some anti-evidentialist philosophers would like you to believe.

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**Note:** I'm very much open to input on how to handle future installments in the series. In particular, I'm not sure how much information to try to cram into one post (this could've easily been two), and I'm not sure if the next post should cover nonevidentialist epistemologies, or if I should just skp straight to skepticism.