The vast amplitude of relevant material daily growing with the growth of knowledge, cannot but hamper the sincerest efforts of those who desire to take a comprehensive view of the great problems which Lord Gifford desired to solve. Most men are amateurs in all departments of activity but the one, be it scientific or practical, or artistic, to which they have devoted their lives. Bacon, indeed, with the magnificent audacity of youth, took all knowledge for his province. But he did so in the sixteenth century, not in the twentieth; and even Bacon did not escape the charge of being an amateur. No one, while human faculty remains unchanged, is likely to imitate his ambitions. More and more does the division and subdivision of labour become necessary for knowledge, as for industry. More and more have men to choose whether they shall be dabblers in many subjects or specialists in one. More and more does it become clear that, while each class has its characteristic defects, both are required in the republic of knowledge. So far as specialists are concerned, this last proposition is self-evident. Specialists are a necessity. And it may well be that those who have successfully pressed forward the conquering forces of discovery along some narrow front, careless how the struggle towards enlightenment fared elsewhere, may be deemed by the historian to have been not only the happiest, but the most useful thinkers of their generation. Their achievements are definite. Their contributions to knowledge can be named and catalogued. The memory of them will remain when contemporary efforts to reach some general point of view will seem to posterity strangely ill-directed, worthless to all but the antiquarian explorers of half-forgotten speculation. Yet such efforts can never be abandoned, nor can they be confined to philosophers. There are for all men moments when the need for some general point of view becomes insistent; when neither labour, nor care, nor pleasure, nor idleness, nor habit will stop a man from asking how he is to regard the universe of reality, how he is to think of it as a whole, how he is to think of his own relation to it. Now I have no wish to overpraise these moments of reflection. They are not among the greatest. They do not of necessity involve strenuous action, or deep emotion, or concentrated thought. Often they are periods of relaxation rather than of tension, moods that pass and leave no trace. Yet it is not always so; and when the pressure of these ancient problems becomes oppressive, then those who, from taste or necessity, have lived only from hour to hour, seek aid from those who have had leisure and inclination to give them a more prolonged consideration.