“[Uccello] would remain the long night in his study to work out the vanishing points of his perspective, and when summoned to his bed by his wife replied in the celebrated words: “How fair a thing is this perspective.'” Being endowed be nature with a sophisticated and subtle disposition, he took pleasure in nothing save in investigating difficult and impossible questions of perspective . . . When engaged in these matters, Paolo would remain alone in his house almost like a hermit, with hardly any intercourse, for weeks and months, not allowing himself to be seen . . . By using up his time on these fancies he remained more poor than famous during his lifetime.”

Vasari, Lives of Artists