The Instructor 3.11.55

White, then, befits peaceful and enlightened people. As signs closest to their causes signify their presence, or rather show the existence of what produced them, as smoke shows fire, and good color and a good pulse show health, so among us such dress shows the state of the character. Self-control is clean and simple, since cleanliness is a disposition that prepares a pure way of life unmixed with shameful things, and simplicity is a disposition that removes superfluities. Solid clothing, and especially undressed wool, keeps in the heat of the body, not because the clothing has heat in itself, but because it turns back the heat going out from the body and gives it no passage; and if any heat falls on it, it takes it in, keeps it, and, warmed by it, warms the body in return; so it should be used especially in winter. It is also a sign of contentment; and contentment is a disposition without superfluity, receptive of what is sufficient for a life lacking nothing according to reason, a healthy and blessed life.