Italian contributions in the field of crowd and group psychology are represented by Paolo Orano’s _Psicologia sociale_, which includes only a partial treatment of the subject that is indicated by the title; and by Scipio Sighele’s _La foule criminelle_ and _Psychologie des sectes_. Permanent groups, according to Sighele (following Tarde), are either sects, castes, classes, or states.[XXII-36] The sect is a group of individuals which possesses a common ideal and faith, such as a religious denomination or a political party. The caste arises from identity of profession. The class is characterized by a strong unity of interests. States possess common bonds of language, national values, and national prestige. The concept of “consciousness of kind” was developed by Franklin H. Giddings in his _Principles of Sociology_ (1896). Consciousness of kind is the original and elementary subjective fact in society.[XXII-37] Professor Giddings defines this term to mean “a state of consciousness in which any being, whether low or high in the scale of life, recognizes another conscious being as of like kind with itself.” In its widest meaning, consciousness of kind marks the difference between the animate and the inanimate. Among human beings it distinguishes “social conduct” from purely economic or purely religious activity. Around consciousness of kind, as a determining principle, all other human motives organize themselves. People group together according to the development of the consciousness of kind in them. Roughly speaking, there are four such groupings.[XXII-38] (1) The non-social are persons in whom the consciousness of kind has not yet developed--in whom it finds imperfect but not degenerate expression, and from whom the other classes arise. (2) The anti-social, or criminal, classes include those persons in whom the consciousness of kind is approaching extinction. They detest society. (3) The pseudo-social, or pauper, classes are characterized by a degeneration of the genuine consciousness of kind. (4) The social classes are noted for a high development of the consciousness of kind; they constitute the positive and constructive elements in society. At the head of the list are the pre-eminently social. These people devote their lives and means to the amelioration of society; they are called the natural aristocracy of the race, the true social élite. Consciousness of kind is made possible in part by the operation of physical factors. Fertility of soil is one of the sources of human aggregation. Favorable climate makes aggregation possible. Aggregation of population is either genetic (due to the birth rate) or congregate (due to immigration). Aggregation leads to association--the proper _milieu_ for the growth of consciousness of kind.