Today I have been doing some reflecting on knowledge, rationality, and justification. I think it would be helpful to briefly write out my current basic views so that I can keep them in mind more easily and, if it ever becomes necessary, revise them.
Justified True Belief
Knowledge is an essentially contested concept. The traditional definition of (propositional) knowledge is "justified true belief." The problem with this definition is that it is easy to think of examples where a belief is true and justified, yet seemingly fails to count as knowledge. I often think of a specific case that came up back when I was first learning about epistemology.
I was at my friend Matt's house, and another friend named Jessica was there as well. When Jessica arrived, we both saw her carrying a small purse. Later that evening, the three of us were sitting around in Matt's living room talking. At a certain point, Jessica said she had to leave. She stood up and walked to the door, and Matt noticed that she left a small purse behind in her seat. He said, "Jessica, you're forgetting your purse." Jessica stopped, looked at her hands, and said, "You're right!" Then she turned and walked across the room to a completely different spot and retrieved a purse that neither Matt nor I had taken notice of. Jessica said, "Thank you, I almost left it here!" Then she exited the house, leaving Matt and me puzzling over the other purse that was still sitting there.
Now, in this scenario, Matt saw Jessica leaving behind a purse, and he also remembered that she had arrived with a purse, so he formed the belief, "Jessica is forgetting her purse." This belief turned out to be true, and it also seems to have been justified, since there was good evidence to support it. But it's hard to say that Matt knew that Jessica was leaving her purse behind. After all, if it hadn't been for the small purse that she left behind in her seat, it's doubtful that Matt would have even thought of it. Yet that wasn't her purse! (I can't remember who the real owner of the mystery purse turned out to be. It might have been Matt's mom.)
Cases like these pose a challenge to the traditional definition of knowledge. This would seem to leave us with three options:
- We embrace the traditional definition and accept a more restricted view of what counts as a justified belief. In this case, it follows that Matt's belief was not really justified.
- We add a fourth condition in addition to truth, justification, and belief. In this case, Matt's belief failed to meet whatever this fourth condition was.
- We replace justification with a different condition. In this case, the justification for Matt's belief is irrelevant. He didn't know what he thought he knew because his belief failed in some other way.
Part of the difficulty here is that we are not supposed to equate knowledge with certainty. But the other difficulty is that it's possible for a false belief to be justified. If a false belief can be justified, then it's hard to think that truth is what turns a justified belief into knowledge, since one could apparently have an unsuccessful justification for believing the right thing. So which view of knowledge is the correct one?
Personal Thoughts on Knowledge
I don't personally feel drawn to any of these three views of knowledge. Instead, I will explain the view that I've held for a long time now. First, I think it is important to recognize that, since knowledge is an essentially contested concept, it follows either that people are not going to agree with each other about what it means to know something, or that, when using the word in ordinary conversation, people mean something that is not captured in the above analysis.
It seems to me that in ordinary conversation, we often switch (probably without even realizing it) between two meanings. Sometimes we are referring to beliefs that we are certain of, and other times we are referring to beliefs that we seem to have very, very strong justification for. An example of something I know in the first sense is the fact of my own existence. I am certain of my existence because it is impossible for me to be mistaken about it. I couldn't be mistaken about anything unless I existed. In spite of the fact that some philosophers deny that selves and persons exist, I just can't possibly believe that they're right without denying something that I know with certainty.
An example of something I know in the second sense is the date of my birth. My belief regarding the date of my birth is very strongly justified. It is supported by the unanimous testimony of people who were present for the occasion, and by official government paperwork which corroborates the fact. Somewhat less decisive, but still relevant, is the fact that the recorded date of my birth fits well with my own experience of the timeframe in which I formed my earliest memories, and sufficient similarities between how much I've aged and the general physical appearance of other people in my age group. Is it possible that my belief could still be false? Well, sure. It is perfectly possible that I was born a day earlier, that someone at the hospital made a mistake with my birth certificate, and that by the time they noticed the error, nobody (including my parents) felt like going through the trouble of correcting it. It seems like a highly unlikely scenario, but it's still possible, and for that reason alone I could never have absolute certainty of the matter. But what I do have is reasonable certainty or, at the very least, a belief that is as strongly justified as anyone could reasonably expect it to be.
My claim, then, is that much of what we call "knowledge" is really just very strongly justified belief. This is the only sense I can make of when people say that human knowledge is often provisional, meaning that it could possibly be overturned by future evidence (note that I say "possibly" and not "probably"). If knowledge entails truth, then this idea of provisional knowledge is incoherent. A true belief could not be overturned by any amount of evidence. But what can be overturned is our justification for a belief, even if that justification is very strong.
This is why I'm personally not interested in trying to settle a debate about the correct definition of knowledge, since I don't think a single definition could be given that encompasses everything people mean by using the word in ordinary conversation. If we go that route, we get stuck in sterile debates about the difference between knowledge and certainty, and the fact that we could justifiably hold true beliefs without knowing them. It's not an unimportant topic, but it's not the one I really care about. As far as I'm concerned, when it comes to debates about big topics like free will and mind-body dualism, to say nothing of the existence of God, I am less interested in figuring out what we know than I am in identifying beliefs that we are justified in accepting.
Of course, if it is possible to have certainty about any relevant beliefs, then I want to identify those beliefs, since they will be very important. It's just that I doubt there are going to be many significant cases in which this happens. And obviously my desire is to have the strongest possible justification for my beliefs, but even if justification is not as strong as I wish it were, I am still very interested in knowing whether certain beliefs are justified at all.
Justification
So what is justification? Obviously, it has to do with rationality. Rationality is similar to morality. A moral person is someone who tries to do what is good, and a rational person is someone who tries to believe what is true. In each case, there is a normative element involved. Just as I have moral obligations, I also have rational or epistemic obligations. These are duties, things that I ought to do. And we can use the language of justification in both contexts as well. Morally, if I am justified in taking a course of action, then I am doing the right thing, or at the very least, I am not doing anything wrong. In a similar way, if I am justified in believing certain things, then I am doing the rational thing, or at the very least, I am not doing anything irrational.
I am not sure if the analogy between morality and rationality breaks down somewhere, but that doesn't concern me here. What I'd like to do is briefly set out my thoughts concerning two debates related to justification: the internalist/externalist debate, and the foundationalist/coherentist debate.
My understanding is that internalists believe that justification depends entirely on factors that are internal to a person, whereas externalists believe that external factors play a role. I am inclined to take the internalist view. For instance, if I was trapped in the Matrix without realizing it, would that mean that I was irrational for accepting the world around me as real? I can't see why. Even though my belief in the reality of the world around me would be false, I can't see that I would be failing in my rational duty just by taking the reality of my world for granted. However, if I was confronted with evidence that I was trapped in the Matrix, then the situation would change. I could no longer just look at the world around me and rationally conclude that it's real. Instead, I would have to either abandon my old belief, or I would have to justify my belief by showing how the evidence in question is not strong enough to challenge it.
This fits nicely with a foundationalist theory of justification. This theory holds that beliefs are not always justified by other beliefs, otherwise we would end up with a vicious regress. Instead, there are some beliefs that are "properly basic," meaning that we are justified in holding them even though they are not supported by other beliefs. This includes beliefs that are seen to be logically necessary (like my belief that 2+2=4) or that we can't possibly be mistaken about (like my belief that I exist), but I would opt for the version of foundationalism that also includes weaker beliefs like beliefs based on memory and perception. This has important ramifications. Just because a belief is properly basic, that doesn't mean that it can't be defeated by new evidence. I might be perfectly rational to believe that I am seeing a real tree up until someone informs me that I'm standing in a place (say, an amusement park) where they have planted realistic-looking fake trees all over the place for the purpose of creating a certain ambience. In that case, my belief that I am seeing a real tree would no longer be justified, at least not until I identified a good reason to keep on holding it.
As for coherentism, I can't say I see much wisdom in it. Coherentism apparently holds that beliefs can only be justified by other beliefs, and beliefs are justified when they are seen to be logically compatible with other beliefs that are already held. I am not sure how this could work though. The "other beliefs" would presumably have to be justified already, but that would seem to land us in a minefield of circular reasoning. In fact, one of the main problems with coherentism is that it seems to create a vicious circle: belief A is justified by belief B, which is justified by belief C, which is ultimately justified by belief A. This makes no sense, since a belief can't justify itself.
Perhaps there is a more plausible way to characterize coherentism, but for now I don't see it. Maybe that is because I hold to a correspondence theory of truth, rather than a coherence theory. But I will save that discussion for another post.
One last thought here. I was reading today about how foundationalists face a difficulty in trying to explain how basic beliefs can confer justification on non-basic beliefs. I imagine that there's a lot more to this debate than I realize, so I want to revisit this topic down the road and see if what I'm saying here actually makes sense. But my gut reaction is to think that properly basic beliefs can confer justification on non-basic beliefs in at least a couple of ways.
Sometimes it would surely be via a process of simple deduction. If we can know certain simple mathematical truths in a properly basic way, this would seem to justify more complicated mathematical truths that would otherwise evade us. To use an extremely simple example, I may not be able to just "see" that 200×20=4000, but it is very easy to prove the truth of this based on simpler mathematical formulas that are easier to grasp in a basic way.
Other times, I would think that properly basic beliefs can increase the probability or plausibility of non-basic beliefs. For instance, if I ask for non-alcoholic beer at a bar, but then after a few glasses I find myself feeling drunk, my belief that I am experiencing symptoms similar to drunkenness is properly basic, as is my memory of asking for non-alcoholic beer. Then, assuming that I am still able to do any kind of rational thinking, I can probably correctly infer from this that either the bartender served me alcoholic beer in spite of my request, or someone has drugged my drink, even though neither option is deductively certain. And notice, I would not be irrational for getting myself out of that bar immediately.