Yet into this _complexus_ he must introduce a certain degree of analysis, resolving it into groups and into aspects of facts, or into concurrent elements, which afterwards appear at a certain moment as independent categories. It is the state in a certain form and with certain powers; it is the laws, which determine, by what they command or what they prohibit, certain relations; it is the manners and customs which reveal to us tendencies, needs, ways of thinking, of believing, of imagining; altogether it is a multitude of men living and working together, with a certain distribution of tasks and occupations; he observes then the thoughts, the ideas, the inclinations, the passions, the desires, the aspirations which arise and develop from this varied mode of coexistence and from its frictions. Let a change be produced, and it will show itself in one of the sides or one of the aspects of the empirical _complexus_, or in all of these within a longer or a shorter time; for example, the state extends its boundaries, or changes its internal limits as regards society by increasing or diminishing its powers and its attributes, or by changing the mode of action of one or the other; or, again, the law modifies its dispositions, or it expresses and affirms itself through new organs; or, again, finally, behind the change of exterior and daily habits, we discover a change in the sentiments, the thoughts and the inclinations of the men variously distributed in the different social classes, who mingle, change, replace each other, disappear or reappear. All this may be sufficiently understood, in its exterior forms and outlines, through the usual endowments of normal intelligence which is not yet aided, corrected or completed by science strictly so-called. Assembling within precise limits a conception of such facts is the true and proper object of narration, which is so much the clearer, more vivid and more exact, as it takes the form of a monograph; witness Thucydides in the Peloponnesian war.