Our scientific and technological civilization has flourished by encouraging increasing specialization. The universal man (think Leonardo da Vinci) has not existed since the renaissance. With the rapid multiplication of knowledge and the techniques for storing and transmitting it, the human capacity to absorb and use knowledge is rapidly saturated, so we end up by knowing more and more about less and less, compensating our increasing specialization with a division of labour among more and more specialists, with managers ensuring (hopefully) that everything fits together. This is accompanied by a reductionist approach that assumes that if you know each part, you also know the whole. While this may be true of machines, more complex systems like computer programmes, ecosystems and people show emergent properties that cannot be predicted simply from a knowledge of the component parts.