We are familiar with the statement that the present world-conflagration is, or involves, a struggle between two different philosophies. Obviously the statement is very vague, and it is exceedingly difficult to say exactly what it means. But if it has any meaning at all, a professional philosopher ought to be supremely interested in it. Philosophers are too apt to sit in their ivory towers, weaving curious distinctions and debating strange intellectual puzzles, without any consideration of their implications for humanity. For even the most abstract questions invariably have, in the end, important practical bearings. And we are apt to forget that, in the last analysis, philosophers are the uncrowned rulers of the world. For their ideas, secretly infiltrating among the masses, are among the forces which drive civilizations. Plato has had more influence on the destiny of man than the inventor of the steam engine. And so I make no apology for attempting to discuss here the question whether the two great nations now engaged in war, Germany and Britain, represent any philosophical ideas, what the philosophical issues of the war are, and where, in those issues, the truth, or the greater degree of truth, lies. And the paper will have two parts. In the first I shall try briefly to state what I believe the issues to be. In the second I shall attempt to discover whether there is any rational ground for preferring the philosophy of the one side to that of the other.