Equity, innocence. During the Golden Age this goddess dwelt on earth, but when sin began to prevail, she reluctantly left it, and was metamorphosed into the constellation Virgo.
When hard-hearted interest first began To poison earth, Astræa left the plain.
Thomson: Castle of Indolence, canto 1.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894