Similar to Aristotle, Vitruvius offers admiration for householders who built their own homes without the involvement of an architect.[6][7] Vitruvius’s ambivalence on domestic architecture is most clearly read in the opening paragraph of the Introduction to Book 6.[8] Book 6 focusses exclusively on residential architecture but as architectural theorist Simon Weir has explained, instead of writing the introduction on the virtues of residences or the family or some theme related directly to domestic life; Vitruvius writes an anecdote about the Greek ethical principle of Xenia: showing kindness to strangers.[9]