From food and water, then, we may learn whether sites are naturally unhealthy or healthy. - Vitruvius

In Spring all trees become pregnant, and they are all employing their natural vigor in the production of leaves and of the fruits that return every year. The requirements of that season render them empty and swollen, and so they are weak and feeble because of their looseness of texture. This is also the case with women who have conceived. Their bodies are not considered perfectly healthy until the child is born.

In the midst of all this great variety of subjects, an individual cannot attain to perfection in each, because it is scarcely in his power to take in and comprehend the general theories of them.

For siege works against bold and venturesome men should be constructed on one plan, on another against cautious men, and on still another against the cowardly.