How Do We Know What We Think We Know?

Rationalism. To use a term from computing, Rationalism is the default position. Everyone needs to be rational to survive from day to day. Any other claims for knowledge not based on rational investigation are optional extras. Where they violate reason they are fictions or delusions or romantic fantasies. Where they lie within the bounds of reason (which are not completely determinate) they amount to lifestyle choices, which include ethics where the best choices can be determined by reason, aesthetics where choice is a matter of personal whim and cannot have an adverse affect and politics where choices can have considerable effect but it has not yet become possible to scientifically demonstrate which choice is the best.

Worldviews that have no place for gods or superstition or other fantasies can be traced back to antiquity. I like to think that in any community there have aways been down-to-earth practical people who see the tales told by priests and mythmakers as just that - fiction. Some philosophers regard myths as a means of controlling the mass of people, either by stopping them from thinking clearly (Marx, opiate of the masses) or by providing them with a purpose towards which they will work (Strauss).

Individual Knowledge. How do we individually know what we think we know? For each of us there is the first-hand knowledge that we receive through our senses and from our own thought processes. This can be called direct knowledge. Thus we all have direct knowledge of the place where we live, but there will probably be many other places we have never visited and of which we have only second-hand or indirect knowledge.

Probably the majority of our knowledge is second-hand. We rely upon what various authorities tell us. It therefore becomes very important for us to be able to know how much trust we can put in the pronouncements of these authorities. How do we assess what trust we can put in authorities? For many people it is a simple matter of assessment of the character of the person. Unfortunately unless we really know the person very closely we can often be deceived on this score. How often do we read in the newspapers of naive people being conned out of their savings by convincing rogues, or led astray by charismatic religious or political leaders.

A second way that we can assess someone's trust-worthiness is by the consistency of their ideas. If what they say holds together in a logical manner and does not contain contradictions then we can say they seem to be talking sense.

The third and final way to assess the trustworthiness of an authority is by taking other opinions. If everyone qualified in a subject tells us the same thing then we can be pretty well assured that what they say is true. An important way of ensuring this is the method of peer review employed by reputable scientific journals. But experts have been known to be wrong, this may be because their ideas have become out of date and they have not adapted to new information, or it may be that their scientific ideals have become compromised by their paymasters or by their religious or political allegiances. So, ultimately, we have to learn to think for ourselves.

Collective Knowledge. How Do We Collectively Know What We Know? The basis of the collective knowledge of the human species is the scientific method. How does this work? Simply expressed, it is a cyclical process: (a) We start by gathering evidence, accumulating facts, which we obtain by simple observation or by conducting special experiments to see what will happen under particular conditions. (b) We try to combine these facts into some sort of order. In some cases we may even be able to express relationships between them by mathematical equations. (c) These equations and relationships may then be seen to form part of a larger system of relationships, which constitutes a theory. (d) We can use these theories to make predictions and hypotheses about other events. (e) We then go back to observation and experiment to test out whether our predictions are correct or our hypotheses true.

This process of a virtuous spiral is the way in which we arrive at scientific or rational knowledge. It is a repeated process, that brings us ever more sure knowledge but can never be absolute knowledge. Well known examples of scientific theories are those of Gravitation, Evolution, Relativity and Quantum Mechanics.

I would emphasise that scientific knowledge is not cold and unemotional. It can give us an awesome picture of the universe, vast in space and time, both simple and complex in structure, with both beautiful and horrific aspects.

Belief and Knowledge. Does Belief Differ From Knowledge? People from different backgrounds often seem to understand something different when they use the term ‘belief’. I shall be using it here to mean knowledge which is imbued with feeling to some degree. In fact I take the view, not shared by all rationalists, that feeling underlies the operation of the human faculty of reason. The way it works, I think, is that in deciding whether to believe a statement, especially one that is going to affect our lives closely and on which we may need to take a decision, we weigh up in our minds, possibly subconsciously, our feelings for and against the subject. Think of the symbol of the scales of justice. If our positive and negative feelings on the subject balance and are not too strong we don't particularly care one way or the other about it. If the positive feeling outweighs the negative we accept it as part of our beliefs. On the other hand if we have strong feelings both for and against this may result in emotional turmoil. This may happen for example if we get opposing advice from our parents, or from a parent and a valued teacher.

When the feeling associated with a belief is strong enough to amount to emotion, I think we can talk about believing in something. It has then become a motivational commitment. Personally I would say that I ‘believe in’ reason. Moreover I have good reasons for believing in reason. It is the only sound way to true knowledge. This is in contrast to faith, which is emotional belief in something without good reason. It is irrational belief. Everyone needs the ability to reason, even those whose beliefs are irrational.

This essay is based on a page that first appeared on the Leicester Secular Society website in 2004.