Let us begin with the familiar view that life has a meaning only insofar as we make it meaningful in the way that we live. This is to focus on the value of each individual life, in which respect it may be contrasted with human destiny as being part of a greater scheme of things, as when we look to religion to give significance to our lives beyond our earthly pursuits. What is implied, then, is that human life is devoid of any transcendent meaning, so that we are not the protagonists in a cosmic drama starring Christian or other deities, the final act being that in which we depart this life and set sail for another. On the contrary, when we die we sink into oblivion, and that is all there is to it.

The logical Law of Non-contradiction – that a proposition cannot be both true and false – enjoys a special, perhaps uniquely privileged, status in philosophy. Most philosophers think that finding a contradiction – the assertion of both P and not-P – in one's reasoning is the best possible evidence that something has gone wrong, the ultimate refutation of a position. But why should this be so? What reason do we have to believe it?

A few years ago, I, an American, was giving a talk at a political philosophy conference in the United Kingdom. My topic was religion in democratic politics, and I delivered what I thought was a splendid line of argument supporting the idea that religion has at most a highly constrained role to play in democratic politics. The audience was appreciative enough, but during the question and answer session, there emerged the charge that my paper had addressed a uniquely ‘American’ problem, a problem that was not of general significance to political philosophers outside of the United States. I replied that although the political scene in the contemporary United States provides many high-profile examples of the problem I had been addressing, the general problem of religion in politics confronts democracy as such. I then provided some cases from outside America in which the problem shows itself: the public slaying of Theo Van Gough, the controversy surrounding the publication of cartoon representations of Muhammad in Denmark, the reemergence of religiously-affiliated and reactionary political parties throughout Europe, and so on. Yet for the most part my audience remained unmoved.

In a democracy people are free to express their opinions and question those of others. This is an important personal freedom, and also essential to the very idea of government by discussion. But it has also been held to be instrumentally important because in open public debate true ideas will conquer false ones by their merit, and the people will see the truth for themselves. In other words, democracy has an epistemic function as a kind of truth machine. From this it follows that in a democracy there should be no dogma: no knowledge protected from public challenge and debate. Yet this whole argument is founded on embarrassing misconceptions of the nature of truth and of the working of democracy.

Philosophers and others with inquisitive minds have busied their brains for millennia with questions such as: ‘Does god exist? What is the meaning of life? Are we free or determined? What is truth? Is there any knowledge which is so certain that no reasonable person could doubt it? What is reality? What is good? What is beautiful? Why exist? What is “to be”? What is justice? What did Kant mean by the categorical imperative?’ Are all these topics equally (un)important or is there a ranking of philosophical problems? If there is such a ranking, is there a need to set priorities? What philosophical problem is most urgent?

Over the years, two criticisms of free markets have been repeated over and over again, by very prominent academics. One concerns the subjective theory of values many pro-market economists embrace, the other involves the move from something being good to do to requiring the government to make – or ‘nudge’ – us do it.

In the final chapter of his book, The View from Nowhere, the American philosopher, Thomas Nagel, writes as follows about death:

Damaris Masham has been described as the first woman philosopher of her Age. Her best known works, published anonymously, were ‘A Discourse Concerning the Love of God’, 1696, and ‘Occasional Thoughts in Reference to a Vertuous or Christian Life’, 1705. To some scholars her ideas, radical for her time, are the ideas of an early feminist. Her correspondents besides Locke, included Leibniz. Damaris was 23 years old and Locke 49 when they first met in 1681.

Gottfried Wilhelm Leibniz (1646–1716) was quite a thinker. As a philosopher, he made major contributions to epistemology, logic, the philosophy of religion and metaphysics. He was also an accomplished scientist, historian, and linguist. In mathematics, he built the first (admittedly somewhat unreliable) calculating machine able to perform all four elementary arithmetical operations, and devised the first proper formulation of binary numbers. Although Chinese and Indian scholars had developed several types of rudimentary binary notation centuries earlier, the number system at the heart of every modern computer was put together by Leibniz. As if that were not enough to guarantee his immortality, he also developed calculus independently of Isaac Newton, and it is mostly Leibniz's version that survives in our textbooks, due to his superior notation.

Philosophers write essays. Nowadays most of them are highly technical and argumentative. They have titles like ‘A Rejoinder to So and So’ or ‘A Critique of Such and Such’. This is somewhat understandable. Like others in my field, as a philosopher, my work is predicated on having interlocutors – all of whom, with a few exceptions, I have never met. This is the beauty of the written word combined with public libraries. Because of printing I can engage the ideas of others from a different time or place; because of libraries I am not excluded from the conversation because of social or economic class.

In this dialogue, two college students, Katie and Dennis, discuss some of the positions taken by Sam Harris in his recent work The Moral Landscape. They discover that, first, theories of ethics based on human well-being are nothing new; they also question whether Harris has truly closed the door on moral subjectivism. Next, while remaining sympathetic to Harris, they question how much he has really accomplished by equating human well-being with specific brain states, and wonder if blissful brain states based on delusion can really be associated with a life well lived.