On Architecture

9. Further, it is owing to the rarity of the atmosphere that southern nations, with their keen intelligence due to the heat, are very free and swift in the devising of schemes, while northern nations, being enveloped in a dense atmosphere, and chilled by moisture from the obstructing air, have but a sluggish intelligence. That this is so, we may see from the case of snakes. Their movements are most active in hot weather, when they have got rid of the chill due to moisture, whereas at the winter solstice, and in winter weather, they are chilled by the change of temperature, and rendered torpid and motionless. It is therefore no wonder that man's intelligence is made keener by warm air and duller by cold.

10. But although southern nations have the keenest wits, and are infinitely clever in forming schemes, yet the moment it comes to displaying valour, they succumb because all manliness of spirit is sucked out of them by the sun. On the other hand, men born in cold countries are indeed readier to meet the shock of arms with great courage and without timidity, but their wits are so slow that they will rush to the charge inconsiderately and inexpertly, thus defeating their own devices. Such being nature's arrangement of the universe, and all these nations being allotted temperaments which are lacking in due moderation, the truly perfect territory, situated under the middle of the heaven, and having on each side the entire extent of the world and its countries, is that which is occupied by the Roman people.