Full Idea
Just as the bones, flesh, intestines, and blood vessels are enclosed with skin, which makes the sight of a man bearable, so the stirrings and passions of the soul are covered up by vanity: it is the skin of the soul.
Gist of Idea
Just as skin hides the horrors of the body, vanity conceals the passions of the soul
Source
Friedrich Nietzsche (Human, All Too Human [1878], 082)
Book Reference
Nietzsche,Friedrich: 'Human, All Too Human', ed/tr. Faber,Marion [Penguin 1994], p.62
A Reaction
What a glorious analogy! None of us should underestimate our vanity. The least vain people you ever meet can reveal their vanity if you challenge them close to home. Try accusing them of vanity! Attack their essential character! (No, don't do that).