rights of nationhood, the Statesmen of the Paris Conference are to reply—“We do not know whether your claim is well-founded; for the historians and political philosophers cannot tell us the meaning of the word ‘nation.’ Go to and fight, and, if you survive, we shall recognise the ‘fait accompli’ and hail you a Nation.” I have dwelt at some length on this perplexity of the historian, grappling with the task of defining nationhood, because it illustrates so well a fact on which I wish to insist—namely, that it is not sufficient for the historian and the political philosopher to be willing to recognise the mental factors in the phenomena with which he deals. It is necessary to recognise that these factors are of overwhelming importance, and that they cannot be satisfactorily dealt with by aid of the obscure and confused psychological concepts of popular thought and speech. We must recognise these political problems for what they truly are—namely, psychological through and through, and only to be attacked with some hope of success if we call to our aid all that psychological science can give us. This conclusion cannot fail to be unpalatable to very many workers in this field; for it implies that equipment for such work demands some additional years of preparatory study. But, it may fairly be asked, if the medical man must devote six years to the intensive study of the human body, before he is permitted to practise upon it, and even then without any scientific knowledge of the human mind, should not he who would practise upon the body politic, in which not merely the bodies but the minds of men interact in the most subtle and complex fashion, prepare himself for his exalted task by an even more extended course of study? Prof. Ramsay Muir has the merit of recognising the essentially psychological nature of his problem; for his provisional definition (cited above) is wholly psychological, and he tells us that the essence of nationality is a sentiment; but he reveals the inadequacy of his psychological equipment by telling us in the same paragraph that its essence is a belief, the belief that they are a nation, passionately and unanimously held by the members of some group. If we look again at the list of seven proposed marks of nationhood, we shall see that they are rather of the nature of conditions favourable to the growth of nationhood; and, as we shall find, this list may be considerably enlarged. He comes nearest to the truth perhaps when he says “its essence is a sentiment.” But he does not attempt to tell us what is the nature of this sentiment, nor even what is its object.