On the Art of Building

...so that they may easily go mad, or so that they may easily deliver themselves to destruction, or so that they may easily put an end to their lives by hanging, by leaping from a height, or by iron and poison. Add to this that, once the more secret manifestations of nature have been scrutinized, it is necessary to have weighed whatever pertains to the matter. A custom followed from the time of Demetrius, not only for cities and towns but also for the daily establishment of military camps, is that the livers of the cattle pastured there should be inspected for their condition and color: if they happen to appear infected by some vice, they indicate the unhealthiness of the place, which must be avoided. Varro used to say that he had learned that in certain places, extremely minute living creatures, like atoms, fly through the air, and being inhaled into the lungs, they take hold in the vital organs and, by gnawing, cause dark and wasting diseases, thus bringing pestilence and destruction. Nor should it be passed over that one will find some places that are, by their own nature, free from almost all inconveniences and devoid of dangers, but are so exposed that foreign and adventitious tribes quite often bring pestilence and calamity upon them. And they do not carry this out only by arms and injury, such as those that might be inflicted by barbarian and savage peoples, but they cause great harm through friendship and hospitality. Some who have had neighbors desirous of new things have been endangered by the ruin and loss caused by them. In the Pontus, the Genoese colony is plagued by constant pestilence because slaves are gathered there daily, and they are wasted and diseased from mental distress as well as from the site and the filth. They also affirm that it is the mark of a prudent and well-counselled man to have investigated the future fortune of a region through auspices and by observing the sky. These arts, provided they are in accordance with religion, I do not consider at all to be despised. Who would deny that whatever it is that they call "fortune" has the greatest influence in human affairs? Indeed, shall we not affirm that the public fortune of the city of Rome has had the greatest influence in the expansion of its empire? Diodorus writes that the city of Iolaus in Sardinia, founded by the grandson of Hercules, even though it was frequently harassed by the arms of the Carthaginians and Romans, has nonetheless been eternally free. Is this without the fortune of that place, as at Delphi, where the temple, having first been burned by Phlegyas, burned for a third time in the days of Sulla, which also [happened to] the Capitol...