One of the most common and comical aspects of the lives of very young children that I find quite joyful can be summarized in one word… “Why?” Well, it is more like a sequence of these “Why” questions over and over again until your head is about to explode. Even though there is a silliness to asking “why” so many times in a row, the young child doing so also shows a joyful curiosity that we all share. And, as it turns out, answering the simple question “Why?” is sometimes very hard.
A similar brand of question that receives detailed attention in philosophy is “how do you know?” More specifically, in philosophy there is an entire area of study known as epistemology that aims to analyze what it actually means to know something. While I do not plan to go super deep into epistemology here, it is important to understand such words as believe, know, and certain when we are trying to learn how to carefully have intellectual discussions with others.
My only goal here is to clarify some proper ways to use terms like these within this particular context, because many times these ideas are not understood in a properly nuanced manner.
What is Belief?
This one ought to be the simplest of all, and yet for a couple reasons this has become difficult. The reason is that the word “belief” in popular thought has obtained a new meaning in the religious context. To a great many, the term belief in the context of religions denotes at least a complete vacuity of any evidence or support for the religious position, if not (in extreme cases) an outright denial of all existing evidence. This definition is so biased. I would compare it to a fan of a particular sports team saying that their team is the best team to be a fan of. I honestly think it could even be argued that this definition is a form of either propaganda or outright intellectual discrimination against religious people. A more popular colloquial term for the thing I am trying to describe here is blind faith. Please, please do not take that definition at all seriously if you have been exposed to it. It is completely alien from EVERY religious person, and from every person who has ever lived for that matter. Nobody that I have ever heard of consciously rejects what he or she knows to be evidence without some kind of counterevidence. Let’s respect one another enough to understand the basic idea that everyone has reasons for thinking what they do.
The word belief is really quite simple. A quick Google search gave me the definition an acceptance that a statement is true or that something exists. I am perfectly happy with this definition, as is anyone who holds to a particular religious tradition. When I say that I am a Christian, what I mean by that is that I accept that the core tenets of the Christian religion are true. When a person says that they believe in this religion or that religion, that is all that they mean.
I hate to even have to define the word belief, but I have seen that in some circles (even if very small ones) the word belief has been corrupted in an overtly biased manner, and so I felt the need to clarify outright what I mean when I use this term.
What is Certainty?
Another word that gets misused sometimes is certainty. Clearing this one up is similar to the previous situation – but it is a little different because the terms certain and certainty have two genuine meanings, but these meanings sometimes get blended into one meaning sometimes.
What do I mean by this? The easiest way to distinguish them is to say that certainty has a logical definition and a psychological definition that are both legitimate, but need to be recognized as different. The logical use of the word certain is the kind of thing you get out of formal logic and mathematics – mathematicians are certain that 2 + 2 = 4 because according to fundamental laws of mathematics and logic, this statement must be true. The psychological use of the word certain is not at all related to whether something is true – it relates to what we think or feel about a particular idea. Using the psychological definition, it is entirely possible that I am certain that X is true and you are certain that X is not true. This happens all the time – just listen to any political or religious discussion in the public sphere and you will find people who are (psychologically) certain of two opposing viewpoints. But neither of them are (logically) certain about their views, because logical certainty has no role whatsoever in pretty much every area of thought – even science! We cannot even be logically certain that gravity exists. Logical certainty cannot be obtained by any amount of evidence – only logic. You can be logically certain of Y because X is logically known to be true (i.e. 2 + 2 = 4) and X implies Y (i.e. 2 + 2 = 4 implies that 2 + 3 = 5). That’s about as far as you can go with logical certainty.
The important thing to realize with this distinction is that it is very, very easy for us to treat our own psychological certainty as if it were logical certainty. We should do our best to avoid doing this. We must recognize that we can be wrong about a lot of things, even things that we feel certain about. We must be willing to listen to those who disagree with us – even if we turn out to be right and they wrong, more times than not listening to those who disagree with you will help you understand more deeply what you believe and why you believe it.
What is Knowledge?
I have moved throughout this article from the easy definitions to the difficult ones. The leap from defining belief to defining certainly was in my estimation fairly small, but defining the word knowledge is very nearly impossible. There is an entire field of academic study called epistemology that is built upon attempting to clearly define what knowledge is.
The most fundamental attempt at a definition of what knowledge is is the JTB model – which stands for justified true belief. I’ll give a sketch of the train of thought behind this attempt at defining knowledge. It is fairly obvious that if you know something, then you believe that thing. Furthermore, you can’t actually know something in a proper sense of the word unless it turns out to be true (if what you believe turns out to be false, it will be an example of psychological certainty that fails to qualify as genuine knowledge). But a true belief wouldn’t always count as knowledge. For instance, someone could gain strange but strong belief about something they know nothing about while in a psychedelic trance, but even if they turn out to be correct, none of us would say that they knew that thing was true. Upon reflection, we realize that this is because this individual didn’t have any good reason to believe what they did – their belief was basically random and just turned out to be right. This ‘good reason’ is what the term justified is meant to denote.
As it turns out, epistemologists almost universally reject JTB as a sufficient definition for what knowledge is. Roughly, one big reason for this is that something that appears to be good evidence might not actually be connected to the thing you believe. These are sometimes called Gettier-type counterexamples in honor of a philosopher Edmund Gettier who challenged the JTB model. One popular example of this kind of situation involves watching a sports game. Imagine that you know your favorite team is going to play their rival on TV today, and so you turn on the TV to watch the game. But, unknown to you, there was a channel playing a rerun of last year’s game between the two teams, and instead of watching the game going on this year, you watch last year’s game. As it turns out, this year’s game had a final score of 70-60, which is exactly the same as last year’s game. So, by watching last year’s game on TV, you come to believe that your favorite team won the game this year by a score of 70-60. This belief of yours is true, and since you watched a game on TV in which your team beat their team 70-60, you have a very good reason to believe that this is true. And yet it doesn’t seem like it can be said that you know this.
There are lots of examples like this one, each showing that good justification for believing something might not connect to the thing you believe in the way that you think it does. This is strong evidence that, while JTB is an extremely useful model for defining knowledge, it isn’t always quite right. What ought to be added or modified to fix these situations is debated and is worth thinking about, but for the sake of learning critical thinking skills, using JTB as a background of what it means to know will be good enough to avoid most mistakes.
How Do We Know a Premise?
In a philosophical argument, then, what does it mean to say that we know a premise is true? We must believe the premise, the premise must actually be true, and we must have some good reasons to back up our believing the premise. While epistemology has gone much further than this in discussions of what knowledge is, the simple JTB model will be good enough for the purposes of thinking carefully through our beliefs and through philosophical arguments.