The cause of war is spiritual, not material.... The great wars arose from conflicts as to rights, and the dangerous causes of war are the existence of antagonistic ideas of rights or righteousness.... It is for moral ideas that men are most ready to make sacrifices.[37] A similar criticism is made by Admiral Mahan.[38] In the same way the London _Spectator_ while admitting the truth of the principles outlined in the first part of this book, deems that such facts do not seriously affect the basic cause of war: Just as individuals quarrel among themselves, and fight as bitterly as the police and the law courts will allow them, not because they think it will make them rich, but because their blood is up, and they want to stand up for what they believe to be their rights, or to revenge themselves for wrongs done to them, as they think, by their fellows, so nations will fight, even though it is demonstrable that they will get no material gain thereby.... They want sometimes freedom, sometimes power. Sometimes a passion for expansion or dominion comes over them. Sometimes they seem impelled to fight for fighting's sake, or, as their leaders and rhetoricians vaguely say, to fulfil their destinies.... Men fight sometimes for the love of fighting, sometimes for great and noble causes, and sometimes for bad causes, but practically never with an account-book and a balance-sheet in their hands. I desire to give every possible weight to this plea, and not to shirk a detail of it, and I think that the pages that follow cover every one of the points here raised. But there is a whole school of philosophy which goes much farther than the _Spectator_. The view just cited rather implies that though it is a fact that men settle their differences by force and passion, instead of by reason, it is a regrettable fact. But the school to which I refer urges that men should be encouraged to fight, and that war is the preferable solution. War, declare these philosophers, is a valuable discipline for the nations, and it is not desirable to see human conflict shifted from the plane of physical force. They urge that humanity will be permanently the poorer when, as one of them has put it, the great struggles of mankind become merely the struggles of "talk and money-bags."