Show me your warrant.

Imagine yourself on a walking holiday in the Lake District with an optimist. Despite forecasts of heavy rain, the optimist is convinced that the weather tomorrow will be fine, and plans a serious walk. As it turns out, the weather is perfect. The optimist triumphantly says 'You see; I knew it would be fine.' However, there is a sense in which they did not know. They had no good reason even to think that there would be no rain, and were right by pure chance.

Is Christian belief similar? If Jesus were to return tomorrow, and a Christian were to say 'You see, I knew it,' would they be misusing the word 'know' in precisely the same way? This is the question Alvin Plantinga addresses in his warrant trilogy. The main concept Plantinga uses is 'warrant': That quantity, enough of which makes true belief into knowledge. He begins by trying to answer the question 'just what is warrant?' This is a typical philosophical question, and comes with some typical philosophical issues.

We human beings, who spend most of our time interacting at sensible speeds with objects about the same size as ourselves, have developed language to allow us (among other things) to communicate truth about the world in which we live. In doing so, we have given words meanings. A philosopher, seeing that people use a word like 'exist', may wonder precisely what that word means. They will not be satisfied with the synonym-based definitions in dictionaries; they want to get to the heart of the matter.

Unfortunately, although we all get along perfectly well using the word in normal life, we become very confused trying to apply the word in extreme special cases (do possible worlds exist?). There may not be any precise formulation which captures the meaning of the word and corresponds to our intuitions in all special cases. One skill philosophers have honed is finding how close to this ideal they can get. In the course of their investigations, they have discovered that finding the meaning of words is hard, and often impossible.

Sometimes, if you are very lucky, it is possible to find a precise definition of an idea which is both helpful for talking about the world and close to the meaning of the original word. If this project is successful enough, the meaning of the word will eventually change to fit the definition. Something of this kind has happened with words like 'energy' and 'symmetry'. These definitions are often 'definitions in use': Rules for turning sentences involving the word into other sentences with the same meaning not involving the word. Unfortunately, when this is done successfully, the word is normally claimed in the name of science or mathematics.

More often, as with words like 'self', there is a definition-in-use which is helpful for talking about the world and fits very roughly with the original word, corresponding closely in some situations and deviating wildly in others. There may be more than one such definition, in which case philosophical arguments spring up. Occasionally, the project becomes so difficult that philosophers despair of the task. Something like this has happened with words like 'exist'.

What about warrant? Well, Plantinga is not using the word 'warrant' in a standard way; he instead defines it as the quantity enough of which makes true belief into knowledge. So the word whose meaning is being considered is 'know'. Where on the above continuum does this word lie? It has caused so much trouble that the study of it has been given a name of its own: 'epistemology'. Some have despaired of ever understanding it. Most, whilst agreeing that it is a stubbornly difficult case, have kept trying since it is such an important word.

Plantinga follows current fashion in saying that knowledge consists of true belief together with some other quantity: Warrant. In the first book of the trilogy, 'Warrant: The Current Debate', he tears apart several misguided attempts to give a precise definition of warrant. In each case he does so by considering some extreme special cases, in which the purported knower is suffering from severe cognitive dysfunction.

In 'Warrant and proper function', the next book in the trilogy, he suggests his own approach. Having just demonstrated how likely it is that any precise definition can be decimated, he presents a broad-brushstroke picture about which he is careful to make no claim of precision. Except in the heat of argument, he avoids phrasing his idea in terms of 'severally necessary and jointly sufficient conditions'.

The idea is that a belief is warranted if:

1. It is produced by cognitive faculties that are working properly in an appropriate cognitive environment.
   
2. The segment of the design plan governing the production of the belief is aimed at the production of true beliefs.
3. There is a high statistical probability that a belief produced under those conditions will be true.

In using the concept of proper function, this approach recognises that very often we rely on nonconscious processing within our brains to arrive at our beliefs. When I see a face, I do not carefully consider the raw sense-data being sent up the optic nerve from my eye and conclude that it matches a complex structural pattern I have designated as characteristic of faces. Instead, some pre-processing in my brain lets me know directly that it is a face I can see. I trust this pre-processing implicitly, because I know it functions properly. It is by means of this proper functioning that I get my knowledge that it is a face that I see.

It isn't that I say to myself 'My pre-processors are telling me I see a face, and I trust them, so I really must be seeing a face'. I just know, without the need for such redundant reasoning, and I get the knowledge from that pre-processing. The belief has warrant because whatever part of my brain it is that subconsciously recognises faces is working properly.

Plantinga discusses some of the other ways we get knowledge, for example by memory or empathy. He concludes in each case that we get the knowledge via some such process, and that the knowledge has warrant because the process is functioning properly. He is a little short on detail, which is fair enough, as the way in which our brains actually do these remarkable things is not yet well enough understood to give a detailed account.

He also doesn't give a clear explanation of what a design plan (specifications for proper function) is, or what it means for such a thing to be aimed at the truth. Of course, we have an intuitive grasp of this idea. We can imagine a designer designing something. But we can also recognise that something is working properly if we think it was not designed; if we think it was produced by natural selection, for example. It is this sense that Plantinga intends at:

Here I use 'design' the way Daniel Dennet (not ordinarily thought unsound on theism) does in speaking of a given organism as possessing a certain design, and of evolution as producing optimal design.

Plantinga doesn't give details of how, if you come across a system, you can tell if it is functioning properly or what it is aimed at. He delights in not doing so; after all, he thinks that there was in fact an intelligent designer so no further explanation is needed. In this, he is mistaken. For if the definition of 'proper function' is 'functioning in the way that the designer intended', then we would have no way of determining, by observation of the system itself, whether it is functioning properly or not. However, microbiologists (for example) claim to be able to do exactly that; they are working with the intuitive notion of 'proper function', which Plantinga also uses but does not explain.

He thinks that the idea of an intelligent designer would explain what it is for a thing to be designed. But in that case, to determine the design plan of something, it would be necessary to know the mind of the designer (in this case, of God). But to say that the explanation of a difficult philosophical idea is that it may be found in the mind of God (as Plantinga does with many ideas, such as number, proposition, proper function and therefore also warrant and knowledge) is to say nothing. There is no more content there than in the more colloquial 'God knows'.

Ranting aside, however, the link Plantinga establishes between our ideas of knowledge and of proper function is valuable. The intuitive notion of proper function should suffice for the rest of this post. This account of warrant isn't quite right; it faces some minor technical difficulties. It does provide a strong enough support for a discussion of whether Christian belief is warranted, a topic which he tackles in the final book of the trilogy, 'Warranted Christian Belief', which I'll discuss in my next post.