diminution of war, and modestly casts doubt on all those who believe that the tendency of the world's history is in the direction of such a diminution. An honest and careful record of facts, however, is always valuable. Dr. Woods' investigation will be found useful even by those who are by no means anxious to throw cold water over the too facile optimism of some pacifists, and this little book suggests lines of thought which may prove fruitful in various directions, not always foreseen by the authors. Dr. Woods emphasises the long period in the history of the human race during which war has flourished. He seems to suggest that war, after all, may be an essential and beneficial element in human affairs, destined to endure to the end, just as it has been present from the beginning. But has it been present from the beginning? Even though war may have flourished for many thousands of years--and it was certainly flourishing at the dawn of history--we are still very far indeed from the dawn of human life or even of human civilisation, for the more our knowledge of the past grows the more remote that dawn is seen to be. It is not only seen to be very remote, it is seen to be very important. Darwin said that it was during the first three years of life that a man learnt most. That saying is equally true of humanity as a whole, though here one must translate years into hundreds of thousands of years. But neither infant man nor infant mankind could establish themselves firmly on the path that leads so far if they had at the very outset, in accordance with Dr. Woods' formula for more recent ages, "fought about half the time." An activity of this kind which may be harmless, or even in some degree beneficial at a later stage, would be fatally disastrous at an early stage. War, as Mankind understands war, seems to have no place among animals living in Nature. It seems equally to have had no place, so far as investigation has yet been able to reveal, in the life of early man. Men were far too busy in the great fight against Nature to fight against each other, far too absorbed in the task of inventing methods of self-preservation to have much energy left for inventing methods of self-destruction. It was once supposed that the Homeric stories of war presented a picture of life near the beginning of the world. The Homeric picture in fact corresponds to a stage in human barbarism, certainly in its European manifestation, a stage also passed through in Northern Europe, where, nearly fifteen hundred years ago, the Greek traveller, Posidonius, found the Celtic chieftains in Britain living much like the people in Homer. But we now know that Homer, so far from bringing before us a primitive age, really represents the end of a long stage of human development, marked by a slow and steady growth in civilisation and a vast accumulation of luxury. War is a luxury, in other words a manifestation of superfluous energy, not