Mathematics has been the most successful and is the most mature of the sciences. Its first great master work – Euclid's ‘Elements’ – which helped to establish the field and demonstrate the power of its methods, was written about 2400 years ago; and it served as a standard text in the mathematics curriculum well into the twentieth century. By contrast, the first comparable master work of physics – Newton's Principia – was written 300 odd years ago. And the juvenile science of biology only got its first master work – Darwin's ‘On the Origin of Species’ – a mere 150 years ago. The development of the subject has also been extraordinarily fertile, particularly in the last three centuries, and it is perhaps only in the last century that the other sciences have begun to approach mathematics in the steady accumulation of knowledge that it has been able to offer. There has, moreover, been almost universal agreement on its methods and how they are to be applied. What we require is proof; and, in practice, there is very little disagreement over whether or not we have it. The other sciences, by contrast, tend to get mired in controversy over the significance of this or that experimental finding or over whether one theory is to be preferred to another.

Some people hope to die in their sleep. Not me. I don't regret having been oblivious at my birth, but I don't want death to catch me napping.

My impression is that the fire-breathing atheists about whom we hear so much – the celebrated quartet of Richard Dawkins, Christopher Hitchens, Sam Harris, and Dan Dennett – think of religious commitments in terms of mistaken or at least hopelessly improbable and therefore irrational ontology. Believers think that something exists, but the overwhelmingly probable truth is that it does not. I may be wrong that this is what they think, but whether they do so or not, I am sure others do. Yet this interpretation of the issue is itself mistaken, and indeed doubly so. It is mistaken, or perhaps it would be better to say unimaginative or off-key to think of religious frames of mind primarily in terms of belief. And it is similarly misdirected to think that the belief component primarily concerns the existence of anything. I read both these insights into Hume's celebrated works on the philosophy of religion, but their lesson seems never to have been properly absorbed. Even Wittgenstein, I think, although he came close and certainly flirted with more adequate views, failed to take their measure properly, although I will be unable to substantiate that opinion here.

This essay defends the idea of drawing a distinction between two modes of not being religious today: between what I will call atheist disbelief, on the one hand, and a-theist non-belief on the other. The former is the mode which is most often in the news. It is the position that pitches itself against religion. The latter is perhaps easily confused with agnosticism as that is popularly understood. Agnosticism in this sense is a position in which you declare yourself undecided or unsure: one is not sufficiently convinced that God does not exist to affirm a full-blooded atheism, but equally, spiritual conceptions, for example as determined by the Christian Churches, do not persuade you either. The situation as regards what I am calling a-theist non-belief is different again: it is not so much a ‘position’ at all as a non-religious ‘habitus’: the understanding of the world and the significance of your life that characterises the a-theist life is one in which religion and religious beliefs, for the most part, just do not figure or play a part. The a-theist does not have positional stance towards religious beliefs – namely a stance of disbelief – but rather, for the most part, simply has no thoughts about God. While not agnostic, the a-theist resembles the agnostic is this respect: conceptually speaking the a-theist is no closer to atheism than he or she is to religious faith. In my view, while the a-theist habitus is incredibly widespread today it is nevertheless typically overlooked in discussions of contemporary faith and atheism. Perhaps this is because it seems so comparatively unreflective and uncommitted. Nevertheless, I will champion it in this essay.

For many contemporary atheists a significant justification for their belief is the claim that there is no evidence for the existence of God. They compare the lack of evidence for God to the lack of evidence for such beings as leprechauns and goblins. And they point out that for belief in the non-existence of alleged entities such as these it is not necessary to prove the negative, which would not be possible, but it is sufficient to show that after due scrutiny there is a lack of affirmative evidence. We reasonably believe, they argue, that there are no such beings as leprechauns and goblins not because we have found proof that they do not exist but simply because we have found no evidence to suggest that they do exist. And similarly in the case of the existence of God.

There is ongoing debate about whether it is ethically acceptable to allow the creation of cloned embryos in order to produce human stem cells. A cloned embryo is created through a process called somatic-cell nuclear transfer, often known as ‘therapeutic’ cloning. The value of stem cells lies in their capacity to become any sort of cell in the human body. This capacity is particularly useful for treating medical conditions where stem cells can be used to repair or replace damaged tissue. The value of a cloned embryo is that the DNA from a person who needs stem cell treatment can be used to create the clone and thereby minimise the likelihood that any inserted stem cells will be rejected. Research on the use of cloned stem cells is in its earliest stage.

Curtain. On the stage there's a row of about forty heads, of natural size, on a long and narrow white board roughly chest height, arranged facing the audience with equal spaces between them from near the left end of the stage to near its right end. The heads are all identical apart from two features. First, the leftmost head is completely bald, the rightmost head has lots of hair on its scalp, and the amount of hair on the heads increases gradually and uniformly from left to right, so that it is hard to discern a difference between any two consecutive heads. Secondly, the colour of the heads changes from bright red on the left to bright orange on the right, again so gradually that it is hard to discern a difference between any two consecutive heads. Apart from the row of heads the stage is empty, with dark background.

Many people hold that procreation is morally obligatory; one ought to bring children into existence because they benefit by being brought into existence. Often this line of thinking stems from the notion that procreation is intrinsically valuable; procreation should be pursued for its own sake. Other philosophers hold procreation is immoral because of the great harm it causes as a result of climate change, overpopulation, mental illness, and so forth. If current population growth continues, there will be an ever-shrinking supply of fresh water and food, leading to the suffering of future generations.

In a footnote to Chapter 7 of ‘The Open Society and Its Enemies’ Karl Popper describes what he calls the ‘Paradox of Democracy’: the possibility that a majority decides for a tyrant to rule. This is the lesser known paradox of the three to which he pays attention, the other two being the ‘paradox of freedom’ – total freedom leads to suppression of the weak by the strong – and the ‘paradox of tolerance’ – unlimited tolerance leads to the disappearance of tolerance.