Short, Short Course in Epistemology
Truth, Belief, Justification, Knowledge: Overview
In fact, it is not hard to understand truth, belief, justification, and knowledge; but to iron out a lot of details does take a fair amount of prose, so let me first give an idea of where all this prose is headed. [This is from my book-in-progress, in which I do indeed say a lot more about truth, belief, justification, and knowledge.]
A fact is whatever really is so—like Jupiter’s being the most massive planet in the Solar system, or like two plus two’s equaling four, or like tigers’ being striped. If what we say, think, or believe is so really is so—if what we say, think, or believe is factual—then what we say, think, or believe is true; if what we say, think or believe is so really isn’t so, or if what we say, think, or believe isn’t so really is so—if what we say, think or believe is factual really is not factual, or if what we say, think, or believe is not factual really is factual—then what we say, think, or believe is false. Truth and falsity are, then, features of what we say, think, or believe about what really is so or really isn’t so.
When we make arguments, we want them to have the feature of being truth-preserving. We want them to have the feature that if the statements we start off with are true, then the statements we end up with after applying logical reasoning to them are also true. We want them to have the feature that if their premises are true, then their conclusions must be, too. In a word, we want our arguments to be valid. This way, if we accept an argument’s premises, we can be sure that it makes sense for us to accept its conclusion, too—and if we are trying to demonstrate the truth of the conclusion to someone else, we can be sure that if he is rational, he will accept the truth of the conclusion as long as he accepts the truth of the argument’s premises and sees no flaw in the argument. Additionally, we care about the truth of the argument’s premises: we cannot count on the conclusion of an argument whose premises are just wrong, after all. (Garbage in, garbage out!) So, we want our arguments to be sound—we want them to be valid and also to have true premises. We want them to be truth-preserving—but we also want there to be truth to be preserved.
To believe is to mentally agree. It is a particular attitude: the attitude of endorsement; the attitude of affirmation; the attitude of acceptance. It is possible to mentally agree—or to mentally disagree—when there is no fact of the matter about what is being agreed or disagreed with. For example, one may mentally agree that a red dress is prettier than a green dress, when which dress is prettier is purely a matter of personal preference and not of fact. When, however, there is a fact of the matter about what is believed, then belief is propositional belief, and it is belief about what is and is not factual—it is belief about what really is so or what really isn’t so. That’s the kind of belief I’m interested in here: the kind of belief that is either true or false. The belief that God exists is such a belief, as either God really does exist or God really does not exist and therefore belief that God exists is propositional belief.
I am particularly concerned with genuine belief. The God-believer really means it when he says that God exists; he is not merely playing let’s pretend or make-believe. And I am particularly concerned with reflective belief. I am not interested in an attitude of mental agreement adopted simply to fulfill some purpose of the moment; rather, I am interested in the attitude of mental agreement at which someone who took his time to reflect upon whether or not a belief was really true would arrive. This, I take it, is the kind of belief the religious believer has. He is not playing let’s pretend, but really means it when he says that God is real. He has taken his time to reflect upon whether or not God is real and has, upon reflection, arrived at the belief that God is real. His belief is genuine, reflective, propositional belief.
Taking an action may be justified by the foreseeable consequences of that action—or by what one supposes to be the foreseeable consequences of that action—or simply by wanting to so act. Taking an action may be justified by one’s seeing the action as somehow beneficial, or simply by one’s having the desire to act. So, one may attend church because he thinks that to do so has psychological or sociological benefits to him, just as he might eat his vegetables because he thinks that to do so is good for him; or he may attend church simply because he wants to, just as he might play a game of chess just because he wants to. Actions may be justified pragmatically, or they may be justified by no more than one’s own desires.
However, believing, when the belief is a genuine, reflective, propositional belief—one about which there is a fact of the matter and one which is thought, upon sober reflection, to accurately capture that fact of the matter—is justified differently. It is justified by the having of good reason to think that the belief is true—it is justified by solid evidence or by sound argumentation, or at least by firm evidence or by reasonably strong probabilistic argumentation. Genuine, reflective, propositional beliefs are appropriately held when they have good epistemic justification. (I will usually omit the modifying string of words “genuine, reflective, propositional” henceforth, as it should be clear that it is genuine, reflective, propositional belief that I am concerned with when considering belief in God.)
Knowing—not merely believing, but knowing—that a statement is true requires more than simply believing it to be true. Knowing that a statement is true requires that it actually be true, and that it be believed to be true, and that it be reliably believed to be true. (After all, one cannot know what is false, even though he might mistakenly believe that it is; and one cannot know simply by accident—one cannot randomly choose a belief, decide to believe it, and then, if it just happens to be true, claim to have known it all along. And one cannot know if the source of information on which he bases his belief is unreliable.) Depending on how one chooses to use the word “know,” he may insist that the mental processes leading to the belief’s being held be infallibly or universally reliable in order for an epistemic agent truly to have knowledge, but I think it will suffice to require that the mental processes leading to its being believed be ones that generally reliably lead to true belief (at least, to true beliefs of the type in question) and that those mental processes not be infected by error in the case of the particular belief in question.
Unfortunately, we cannot actually verify, to a certainty, when mental processes are generally reliable and not infected by error in the particular case, so when we make ascriptions of knowledge, we approximate reliably true belief by appropriately justified true belief. (It is for that same reason that we are forced to make certain fundamental epistemic and metaphysical assumptions, like the assumption that our own mental processes are at least reasonably reliable or the assumption that there is an objectively existing reality of which our senses give us at least reasonably reliable information, upon which all of our knowledge claims are based.) If an epistemic agent seems to believe what we take to be a true belief with what seems to us to be good epistemic justification of an appropriate sort, then we ascribe knowledge to him. (I include the word “appropriately” and the phrase “of an appropriate sort” so as to circumvent the mildly technical but usually irrelevant Gettier problem, which is partly resolved by taking justified true belief not to be an account of knowledge but to be an account of the ascription of knowledge but which still arises—in a milder, not terribly vicious form—when we ask when the ascription of knowledge is itself well-justified.)
And that’s the short course in truth, belief, justification, and knowledge. Let’s take a little more detailed look at them now. [Which is what I proceed to do in my book-in-progress.]