A fight of old ideas against new ones, a contest of clashing culture levels, a struggle to get old things looked at from a new point of view, these are the features that characterize all efforts after reform. It was said by some of the eighteenth century philosophers that society was held together by agreement in a bond. That is not quite correct. The truth is that society is held together, as is any phase of social life, by a bond of agreement. The agreement is not of the conscious, documentary order, but it is there, and it consists in sharing a common life created and maintained by having a common tradition, and a common stock of ideas and ideals. It is this that makes a man a member of one social group rather than of another--Chinese, American, French, German, or Choctaw. There is no discriminating feature in what is called the economic needs of people. The economic needs of human beings--food, clothing, and shelter, are of the same order the world over. And certainly the fact of a Chinaman sharing in the economic life of Britain, or an Englishman sharing in the economic life of China, would not entitle either to be called genuine members of the group in which he happened to be living. Membership only begins to be when those belonging to a group share in a common mental outfit. Even within a society, and in relation to certain social groups, one can see illustrations of the same principle. A man is not really a member of a society of artists, lawyers, or doctors merely by payment of an annual subscription. He is that only when he becomes a participant in the mental life of the group.[9] It is this common stock of mental facts which lies at the root of all collective ideas--an army, a Church, or a nation. And ever the fight is by way of attack and defence of the psychologic fact.[10]