So, in a few paragraphs, we trace the development of the simple social structure of the early Sumerian cities to the complex city crowds, the multitude of individuals varying in race, tradition, education, and function, varying in wealth, freedom, authority, and usefulness, in the great cities of the last thousand years B.C. The most notable thing of all is the gradual increase amidst this heterogeneous multitude of what we may call _free individuals_, detached persons who are neither priests, nor kings, nor officials, nor serfs, nor slaves, who are under no great pressure to work, who have time to read and inquire. They appear side by side with the development of social security and private property. Coined money and monetary reckoning developed. The operations of the Arameans and such-like Semitic trading people led to the organization of credit and monetary security. In the earlier days almost the only property, except a few movables, consisted of rights in land and in houses; later, one could deposit and lend securities, could go away and return to find one’s property faithfully held and secure. Towards the middle of the period of the Persian Empire there lived one free individual, Herodotus, who has a great interest for us because he was among the first writers of critical and intelligent history, as distinguished from a mere priestly or court chronicle. It is worth while to glance here very briefly at the circumstances of his life. Later on we shall quote from his history. [Illustration: Brawl among boatmen ... (From tomb of Ptah-hetep----Pyramid Age)]