In this piece I explain what I consider to be the purpose of evidence, namely that it is the way to distinguish truth from error. I argue that, if our objective is to hold beliefs that are most likely to be true, then evidence and reason are the only methods we should use to form our beliefs. Note: here I am addressing questions of fact, existence, etc. I am not talking about personal preferences or other purely subjective matters, for which reason and evidence are much less useful instruments.
Truth and Reason
What is the purpose of evidence/reason/rationality/etc? What is it for? Why do we bother with it? Why not just believe whatever is convenient, or whatever makes us feel nice, or whatever gives us hope, or whatever is most popular, or whatever those in power tell us to believe? Certainly one can believe on such bases, but there seems to be something very unsatisfactory about such beliefs. Let me outline some premises.
1. Our purpose here (i.e. for this analysis) is to have beliefs that are most likely to be true/accurate/reliable (let’s not quibble on exact words for now)
2. Of the many different possible ways to form beliefs, some are more prone to error than others
3. The least error prone method of forming beliefs is by using reason and evidence (broadly defined)
4. Therefore, we should only form beliefs on the basis of reason and evidence
It should be understood that I advance (3) largely as a matter of definition – that as, I define ‘reason and evidence’ as being those ways of arriving at beliefs which are most consistent with our goal of having true beliefs and avoiding false beliefs. Such ‘reasoning and evidence’ can take many forms, including scientific reasoning, philosophical reasoning, the historical method, legal evidence, naive sensory observation, etc. Needless to say, the specific forms of evidence and modes of reasoning that are applicable can differ considerably from one instance or subject matter to another, nor is it necessarily the case that everything that is claimed to constitute ‘reasons’ or ‘evidence’ is actually worthy of such an appellation, but nonetheless my core thesis stands, namely that it is reason and evidence alone of all the possible modes of belief formation which allow us to form beliefs with a minimum of error. This is not to say that reason and evidence are infallible, or that they can yield certainty. Infallibility and certainty are utterly beside the point. What is crucial, rather, is maximising the chances of finding truth and minimising those of arriving at falsehoods. Reason and evidence are, I argue, precisely those things which best enable us to cleave truth from error in the cleanest, most reliable way possible.
Truth be told, I take it that everything I have said thus far, subject to some minor disagreements about methods of phrasing and precise usage of terms, should be utterly uncontroversial. Indeed, many readers will (I hope) wonder why I have bothered to make the above claims at all, given how apparently innocuous and self-evident they are. Nevertheless, it seems to me that it is necessary, far more often that one may think, to assert this basic point, that beliefs should only be formed on the basis of reason and evidence, for it is, at least to me, disturbing how often this fundamental notion is apparently forgotten, or even dismissed outright, by intelligent people who should know better.
Let me take particular issue with Christians, something I am rather want to do. Certain Christians have, on many occasions, said something similar to the following to me:
“Belief in God isn’t all about evidence or reason. That’s not the most important thing. Its about having a personal relationship with God, not knowing certain facts”
Let us consider this statement, and many others like it that I have heard (other examples would be things like “God is love” or “through faith in Jesus all can be forgiven”). First notice its form: it is a proposition. It asserts some factual claim about the way the world actually is. Being a proposition, it has a truth value. It could be true, it could be false, or maybe it could be neither (depending upon your disposition toward many-valued logics), but the point it that it has a truth value that we would like to evaluate. So how can we tell if this claim is (probably) true or (probably) false? As per my argument above, the answer is, of course, we should use reason and evidence! What type of reason and evidence? Well, that is a deep and tricky question. I’m certainly not saying that this claim needs to be experimentally tested, but it does need to be tested in some way. Some argument needs to be made, some reasoning analyzed, some evidence examined, in order to discern between the case where this proposition is true, and the case where it is false. One could simply believe this claim because it sounds nice, because it brings hope, or because it fits with one’s subjective experiences of life in general, but none of those things will be able to tell us whether the claim is actually true or not.
So, when a Christian says to me that something other than reason or evidence is responsible for some belief that they have, what I hear them saying is something to the effect that “I first and foremost care about something else other than whether this belief is actually true or not”. To this I say: No! Never! Get thee hence, Satan, father of lies! Truth first and foremost. Truth above all. Truth may be subtle and delicate, only to be seen partially obscured or in glimpses from the corner of one’s eye, but that does not make her any less worthy in seeking. I will not settle for anything less.