It is related, says Vasari, of this master, that being commissioned to
paint a picture of St. Thomas seeking the wound in the side of Christ,
above the door of the church dedicated to that saint, in the Mercato
Vecchio, he declared that he would make known in that work, the extent
of what he had acquired and was capable of producing. He accordingly
bestowed upon it the utmost care and consideration, and erected an
enclosure around the place that he might not be disturbed until it
should be completed. One day, his friend Donatello met him, and asked
him, "What kind of work is this of thine, that thou art shutting up so
closely?" Paolo replied, "Thou shalt see it some day; let that suffice
thee." Donatello would not press him, thinking that when the time came,
he should, as usual, behold a miracle of art. It happened one morning,
as he was in the Mercato Vecchio, buying fruit, he saw Paolo uncovering
his picture, and saluting him courteously, the latter anxiously demanded
what he thought of his work. Donatello having examined the painting very
closely, turned to the painter with a disappointed look, and said, "Why,
Paolo, thou art uncovering thy picture at the very moment when thou
shouldst be shutting it up from the sight of all!" These words so
grievously afflicted the painter, who at once perceived that he would be
more likely to incur derision from his boasted master-piece, than the
honor he had hoped for, that he hastened home and shut himself up,
devoting himself to the study of perspective, which, says Vasari, kept
him in poverty and depression till the day of his death. If this story
be true, Uccello must have painted the picture referred to in his old
age.