It is a great honour, and a great responsibility, to be invited to give one of the Installation Lectures on this auspicious occasion. I am ill qualified for this task; but at least I may justly claim that the subject on which I have chosen to speak is one that is of the greatest importance to every university in every part of the world. In England, at least, we sometimes forget that our universities owe their origin and their development in great part to the demands of practical affairs. They arose in the Middle Ages, mainly to provide better education for the hosts of ‘clerks’ or subordinate clergy who undertook all the tasks in mediaeval society for which some degree of learning was necessary.