A certain school of writers, among them Paul Lilienfeld, Auguste Schäffle, and René Worms, have sought to maintain, to extend, or modify the biological analogy first advanced by Spencer. In doing so they have succeeded sometimes in restating the problem but have not solved it. René Worms has been particularly ingenious in discovering identities and carrying out the parallelism between the social and the biological organizations. As a result he has reached the conclusion that, as between a social and a biological organism, there is no difference of kind but only one of degree. Spencer, who could not find a "social sensorium," said that society was conscious only in the individuals who composed it. Worms, on the other hand, declares that we must assume the existence of a social consciousness, even without a sensorium, because we see everywhere the evidence of its existence. Force manifests itself by its effects. If there are certain phenomena that we can only make intelligible, provided we regard them as the products of collective social consciousness, then we are bound to assume the existence of such a consciousness. There are many illustrations ... the attitude for example, of a crowd in the presence of a crime. Here the sentiment of indignation is unanimous. A murderer, if taken in the act, will get summary justice from the ordinary crowd. That method of rendering justice, "lynch law," is deplorable, but it illustrates the intensity of the sentiment which, at the moment, takes possession of the social consciousness. Thus, always in the presence of great and common danger the collective consciousness of society is awakened; for example France of the Valois after the Treaty of Troyes, or modern France before the invasion of 1791 and before the German invasion in 1870; or Germany, herself, after the victories of Napoleon I. This sentiment of national unity, born of resistance to the stranger, goes so far that a large proportion of the members of society do not hesitate to give their lives for the safety and glory of the state, at such a moment the individual comprehends that he is only a small part of a large whole and that he belongs to the collectivity of which he is a member. The proof that he is entirely penetrated by the social consciousness is the fact that in order to maintain its existence he is willing to sacrifice his own.[33]