Grounds for believing

Newman is arguing against an idealised version of reasoning of the kind espoused by John Locke. According to Locke, we must not assent to any proposition without adequate argument or evidence. Assent must come from either logic or from observation. If we assent to a proposition without adequate evidence, we show a disregard for the truth.

Newman thinks that, if we investigate how and why we come to believe things in ordinary life, we will find that things are not so sanitised.

Understanding and apprehending

Firstly, Newman makes a distinction between believing a fact to be true because we understand it, and merely apprehending the truth of a fact.

There are many things that we believe, that we are certain of without having any real evidence for them.

Now, a Lockean might reply that Newman was wrong about this because he might have been made Emperor of the French - it wasn’t so impossible as, for example, 1+1=3.

But Newman doesn’t buy that. He thinks it is beyond ridiculous. He would have to be mad.

Inference and the Illative sense

So why do we believe these things? Newman points out that there are lots of things that we assent to without actually interrogating the evidence. Most of us will believe that there is a North Pole without ever having been there, for example. We haven’t gathered together our sources and investigated their trustworthiness and produced a syllogism or modus ponens to establish the truth of the existence of the North Pole.

Our everyday lives are full of such beliefs - things that we take to be true without argument or evidence. When we wake up in the morning, we don’t count our legs before we get out of bed. We don’t infer from the evidence that swearing at our parents would be rude. We don't have to work these things out - we just know these things to be true. We live as if they are true.

Assent doesn’t always come about as a result of careful inferences. More often than not, it comes about as a result of, Newman thinks, a mysterious cumulation of probabilities of lived experience.

At some point, facts stop being mere probabilities and become certainties. ‘There is a North Pole’ stops being something which may be untrue, and becomes a fact by which we order our experiences.

Newman concludes that we must, therefore, have some particular mental power to bridge the gap between a formal logical and evidential argument and the haphazard nature of everyday life. He calls this our illative sense, our ability to judge well whilst reasoning.

One way of thinking of our illative sense is to see it as providing a framework into which we can slot incomplete information, so that we can make decisions - the construction lines of thought.

Is belief in God rational?

Newman argues, then, just as it is not irrational for us to believe in the existence of the North Pole (or a whole host of other propositions) without proof, neither is it irrational to believe in the existence of God. It is perfectly rational to assent to a proposition on trust or on probabilities based on 'inclinations of the heart'. For some, God exists as part of the framework of their life: