I do not believe philosophy is a means to much - I am from the cradle a philosopher of Michael Oakeshott's bent and believe with him that philosophy does not yield a recipe for doing anything, and certainly not for doing politics. But not everything has to be a means to an end.
Philosophy ranks with some other areas of knowledge, the arts and the good life as something you want to do for its own sake.
It has also been argued that because political life involves thinking about complicated matters concerned with ends, and not just means, and that because there are disagreements about which ends should be adopted, it makes sense to think logically. Philosophy as a training can help people think more clearly.
But I believe passionately that what matters is not so much philosophy as a philosophical attitude. The big problem of our democracy is not the substance of positions taken but rather the level of discourse. It is pretty difficult to run a democracy. One of the things that makes it difficult is that a lot of people do not really like the idea of a democracy, even if they pay lip service to it, and would like to undermine it.
Some of these are overt, like those in the British National Party. The much more dangerous ones are covert to the extent that they would not recognise this self-description. The way in which the tabloids tend, with honourable exceptions, to characterise political positions on either side of the spectrum is so debased that it threatens democracy.
It is extremely difficult to persuade sensible people to take an interest in democratic debate if it oversimplifies and consists of uninteresting mudslinging. To read Hansard from 50 years ago is to realise that this has grown much worse. It has become unfashionable to adopt anything like a philosophical attitude to anything that is said in the course of politics.
This means it is unfashionable to consider the reasons your opponent has for saying what he or she says, and there is a wilful ignoring of the second-order implications of what is said.
I do not believe that anyone in politics says things without having in mind some end that their opponents would recognise as having at least some claim to validity. Proper political discussion should be a conversation about whether that end is superior to other ends and whether the means chosen are appropriate.
But accounts of what is said in the tabloids or by politicians show no acknowledgement that opponents have a reason for saying what they say, that their claims to validity should be recognised or that there may be different and competing ways of achieving a mutually acknowledged end.
The issue of second-order implications is more distressing. This is where a philosophical attitude comes into its own. What politicians say, and how they say it, has an effect beyond the substance of what they are discussing. To make an argument in a certain way creates a precedent. It will influence how subsequent arguments are made and views of what it is legitimate to say - much of party politics consists of the shifting of the centre ground of debate.
Only if politicians are aware of those second-order implications - reflecting on the longer-term, deeper effects of what they say on how people will subsequently discuss and do things - can they can contribute to the maintenance of rational democracy, and ultimately to the survival of democracy at all. The encouragement of a rational, philosophical attitude that recognises layers of meaning and implication is critical to that maintenance. This is something to which philosophy can make a particular contribution.
This is an edited version of Oliver Letwin's talk at last week's "Does Philosophy Matter" debate, staged by the British Academy and The Philosophers' Magazine .
Shadow home secretary