Despite this range and diversity of topics, there is a common underlying theme. Education ought to be devoted, much more than it is, to the exploration real-life, open problems; it ought not to be restricted to learning up solutions to already solved problems - especially if nothing is said about the problems that provoked the solutions in the first place. There should be much more emphasis on learning how to engage in cooperatively rational exploration of problems: even five year olds could begin to learn how to do this. A central task of philosophy ought to be to keep alive awareness of our unsolved fundamental problems - especially our most fundamental problem of all, encompassing all others: How can our human world - and the world of sentient life more generally - imbued with the experiential, consciousness, free will, meaning and value, exist and best flourish embedded as it is in the physical universe? This is both our fundamental intellectual problem and our fundamental problem of living. 

As far as the latter is concerned, we are at present heading towards disaster - as our immense, unsolved global problems tell us: population growth, destruction of natural habitats and rapid extinction of species, vast inequalities of wealth and power around the world, pollution of earth, sea and air, our proclivity for war, and above all global warming. If we are to resolve our conflicts and global problems more intelligently, effectively and humanely than we have managed to do so far, then we have to learn how to do it. That, in turn, requires that our institutions of learning, our universities and schools, are rationally designed and devoted to the task. At present they are not. That is the crisis behind all the others. From the past we have inherited the idea that the basic intellectual aim of inquiry ought to be to acquire knowledge. First, knowledge is to be acquired; then, secondarily, it can be applied to help solve social problems. But this is dangerously and damagingly irrational, and it is this irrationality that is, in part, responsible for the genesis of our current global problems, and our current incapacity to solve them. As a matter of supreme urgency, we need to transform academia so that it becomes rationally devoted to helping humanity learn how to make progress towards as good and wise a world as possible. This would involve putting problems of living - including global problems - at the heart of academia, problems of knowledge and technological know-how emerging out of, and feeding back into, the central task to help people tackle problems of living in increasingly cooperatively rational ways. Almost every department and aspect of academia needs to change. We need a new kind of academic inquiry devoted, not just to knowledge, but rather to wisdom - wisdom being the capacity to realize what is of value in life for oneself and others, wisdom including knowledge and technological know-how, but much else besides. 

So, this is what these essays seek to provoke: a concerted effort to transform our institutions of learning so that they become rationally and effectively devoted to helping us learn how to create a wiser world. 

With these essays before me, I can see that there is one crucial element of learning about which they say nothing - or nothing explicit. The vital role of play in learning. All mammals - or at any rate almost all mammals - learn by means of play. Cats, tigers, foxes and other predators learn to hunt by means of endless mock fights when kittens and cubs. Deer, sheep and antelope learn to escape by means of playful leaps and bounds when young. We are mammals too. Almost certainly, we learnt how to be adult human beings by means of play during the millions of years we evolved into homo sapiens living in hunting and gathering tribes. Children today, out of school, learn by means of play. Learning by means of play is almost certainly fundamental to our makeup. Education needs to exploit it. Schools and universities need to become places of play. Successful problem solving is often likely to be playful in character. The youthful Einstein called doing physics "getting up to mischief". 

But our most serious problems of living are so grim, so imbued with suffering, wasted lives and unnecessary death that the idea of approaching them in a playful spirit seems sacrilegious. We need to keep alive tackling of intellectual problems so that playful capacities can be exercised - if for no other reason (and other reasons there are, of course, aplenty). There are two really worthy impulses behind all rational inquiry: delight and compassion.