Protected and defended by seven circles of walls, constructed of palaces that serve as dwellings for the citizens, the city is located in a place with an ideal climate, conducive to physical health, and on the slope of a hillside because the air there is lighter and purer.

Once again Campanella engages in an explicit polemic with Aristotle, who had excluded artisans, peasants and those involved in manual labor from the category of full citizenship and from the highest levels of virtue.

In the City of the Sun no occupation is vile or base, and all are of equal dignity—in fact, those workers who are required to expend greater effort, such as artisans and builders, receive more praise.

The only thing that they consider to be despicable is idleness, and in this way they come to privilege the dignity of work and to overturn an absurd conception of nobility, linked to inactivity and vice.

Campanella was greatly interested in all ingenious discoveries, and in The City of the Sun he provides many examples of curious inventions, such as vessels able to navigate without wind and without sails, and stirrups that make it possible to guide a horse using only one's feet, leaving one's hands free.

On the external wall legislators are depicted; and it is here, in "a place of great honor" —but along with Moses, Osiris, Jove, Mercury and Muhammad— that the Genoese sailor recognizes Christ and the twelve apostles.

From a tender age children run around in this theater of knowledge, appropriately guided and following correct itineraries, so that they learn joyously, as if playing a game, without effort or pain.

Moreover, there is a close connection between a person's natural "complexion" or character, which is inborn and not afterwards modifiable, and moral virtue, which needs a suitable terrain in order to take root and prosper.

Sexual generation, on the other hand, must obey strict rules regarding the physical and moral qualities of the parents and the choice of a propitious time for conception, determined by an astrologer.

The religious beliefs of the citizenry, even though they include fundamental principles of Christianity (such as the immortality of the soul and divine providence), form a natural religion that establishes a sort of osmosis between the city and the stars.

The task of the twenty-four priests, who live in cells located in the highest part of the temple, is to observe the stars and, using astronomical instruments, to take account of all their movements.