[99] but the simple wealth of nature is food and shelter, and food is bread and water from the spring, which are both diffused over every part of the habitable world; but of shelter there are two kinds, first of all clothes, and secondly a house, on account of the injuries which result from exposure to cold and heat; each of which protections, if any one chooses to discard superfluous and excessive extravagance, is very easily provided.