Book 2
3.1
The propriety of this division in regard to geography is equally apparent; the object of this science being to determine the limits of that one of the temperate zones which we inhabit. To the east and west, it is true, the boundaries are formed by the sea, but to the north and south they are indicated by the atmosphere; which in the middle is of a grateful temperature both to animals and plants, but on either side is rendered intemperate either through excess or defect of heat. To manifest this threefold difference, the division of tile globe into five zones becomes necessary. In fact, the division of the globe, by means of the equator, into two hemispheres, the one northern, wherein we dwell, and the other southern, points to this threefold division, for the regions next the equator and torrid zone are uninhabitable on account of the heat, those next the poles on account of the cold, but those in the middle are mild, and fitted for the habitation of man.
3.1
Posidonius, in placing two zones under the tropics, pays no regard to the reasons which influenced the division into five zones, nor is his division equally appropriate. It is no more than if he were to form his division into zones merely according to the [countries inhabited] by different nations, calling one the Ethiopian, another the Scythian and Keltic,The ancients named the people of southern Africa, Ethiopians; those of the north of Asia and Europe, Scythians; and those of the north-west of Europe, Kelts. and a third the Intermediate zone.
