From An Introduction by Desmond Morris

When viewing these portraits it is important to make a distinction between nudity and nakedness. To me, these are naked bodies but they are not nudes. Traditionally the nude has one of two agendas – the aesthetic and the erotic. Nudes have their clothes removed to make them more beautiful or more sexy. The reason for stripping away the concealing layers of clothing is either to reveal the glory of human musculature or to expose the more private parts. To these ends, nude models are usually carefully selected to offer us the idealised human body as we would like to see it, rather than as it really is, in Bailey’s book this bias is rigorously avoided. These are not nudes, they are naked people and, as such, they tell us so much more about the species to which we all belong.