The penis can be enflamed or the mind can be enflamed.
I'm sure Kenneth Clark had something to say in his "The Nude: A Study in Ideal Form", (which I haven't looked at).
He said we must distinguishes between 'the naked and the nude. To be naked is to be deprived of our clothes, and the word implies some of the embarrassment most of us feel in that condition. The word "nude," on the other hand, carries, in educated usage, no uncomfortable overtone. The vague image it projects into the mind is not of a huddled and defenseless body, but of a balanced, prosperous, and confident body: the body re-formed".
Furthermore "the word was forced into our vocabulary by critics of the early eighteenth century to persuade the artless islanders [of the UK] that, in countries where painting and sculpture were practiced and valued as they should be, the naked human body was the central subject of art."